gynaecology and obstetrics

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tumors in case of spread through the uterosacral ligament. ...... Krukenberg tumor should be suspected. Krukenberg tumors are defined as an ovarian metastasis ...
MEDICAL IMAGING APPLIED TO

GYNAECOLOGY AND OBSTETRICS

AN UPDATE FOR RADIOLOGISTS 1996

PREFACE

In the past two decades impressive technological advances have led to the development of new technologies applied to the field of Gynaecology and Obstetrics. The residential week and this textbook were conceived with the intent of being a primer in this field, but also an update including all the recent applications of medical Imaging to this field. The first chapter deal with gynaecology, the second with obstetrics. I especially wish to thank Dr. Y. Ardaens, the well known French echographist for his contribution to the week and the course by providing the illustrations included in his monograph ‘Echographie en pratique gynécologique’ that was given to all the participants of the residential week. It is hoped that this book will be useful for all the radiologists, including those in training. I also wish to express my gratitude to my friends, the well known Belgian echographists Dr. F. Avni and his crew member Dr. F. Rypens (ULB), Dr. Ph. Clapuyt (UCL) and Dr E. Goes (VUB) for their uttermost contribution in the field of ultrasonography. Spectacular advances have occured over recent years in other methods of imaging. CT scanning and Magnetic Resonance Imaging have particularly extended the role of the radiologist in the investigation of gynaecological disorders, and have provided him with tools which give information impossible to obtain by conventional radiology or even by ultrasound. I am indebted to Dr. S. Gryspeerdt, Dr. D. Van Beckevoort and Dr. L. Van Hoe (KUL), for their chapters on CT scanning and MRI which give an upto-date appraisal of the role of these modalities in the context of gynaecology. But specific radiological techniques are also still useful for the diagnosis of the female genital tract (Digitalized cystocolpodefecography : Dr. M.-H. Tancredi (Bouge)) and new implementations exist in the field of interventional radiology applied to gynaecology (Dr. D. Henroteaux (Liège)). I wish to express my gratitude to all the contributors to this course.

Dr. Jean-Paul A. Joris President of the RBRS.

Introduction - Inleiding J.P. Joris

INTRODUCTION

De plus en plus, la bataille ‘sur le terrain‘ (turfbattle suivant la terminologie anglo-saxonne) de l’Imagerie Médicale se situera dans l’acquisition de compétences ‘transversales’ - pour employer un concept en vogue dans le monde de l’Education. Ces compétences devront être incontestées et incontestables. C’est le défi auquel les radiologues seront confrontés lors de ces prochaines années. Radiologie interventionnelle, imageries spécifiques (gynéco-obstétricales, imagerie cardiaque, tissus mous...) : le radiologue ne pourra justifier sa position et sa place que par la démonstration de son apport primordial quant aux stratégies diagnostiques, aux algorithmes, au choix et à la domination simultanée des différentes technologies dans un même domaine (Rx, US, TDM, IRM, interventionnel). C’est par ce biais qu’il pourra (re)prendre une position centrale d’interlocuteur privilégié de ses multiples correspondants, généralistes ou spécialistes, ou de ses ‘répondants’ oeuvrant dans les mêmes domaines que lui (gynécologues, obstétriciens, cardiologues, chirurgiens vasculaires ...etc.) mais avec des abords technologiques plus restreints. Il doit et devra de plus en plus faire valoir ses compétences, son ‘expertise’ de manière transversale : pour connaître l’imagerie IRM du coeur et des gros vaisseaux, il faut connaître bien entendu la physiologie, l’anatomie, mais aussi la pathologie, les techniques de base d’imagerie, l’échocardiographie, les techniques connexes (scanner spiralé ...etc) et de plus maîtriser les principes de la radioprotection.

Il n’en va pas autrement des autres domaines de l’Imagerie. Ces compétences variées (embryologie, anatomie foetale, pathologie cardiaque, radiologie interventionnelle, gynécologie...) sont d’ailleurs inscrites dans les guidelines de la formation en Imagerie médicale proposés au niveau Européen (AER : guidelines EUCORE - cfr. publication dans la revue ‘Artefact’ d’avril 1996). Or ces diverses notions n’ont pas toujours fait l’objet d’une étude approfondie au cours du cursus de tous les radiologues.

C’est pourquoi la Société Royale Belge de Radiologie a décidé de mettre sur pied des stages résidentiels en Imagerie spécifique, sur base d’une semaine de cours intensifs. Outre le cours en Imagerie Gynéco-Obstétricale, d’autres semaines de formation sont prévues en Imagerie CardioVasculaire (coeur & gros vaisseaux Thoraciques) et en Imagerie des Tissus Mous. Début 1997 en effet aura lieu une semaine d’Introduction à l’Imagerie Cardiaque. En 1998 se déroulera une semaine en Imagerie des Tissus Mous. C’est ainsi que la Société Royale Belge de Radiologie entend concrétiser toujours plus la mission d’enseignement qui lui est dévolue et qu’elle remplit admirablement depuis nonante ans avec une vitalité et un enthousiasme sans cesse renouvelés.

Docteur Jean-Paul JORIS Président de la Société Royale Belge de Radiologie.

INLEIDING

De strijd van de medische beeldvorming ‘op het terrein’ (de turfbattle volgens de Angelsaksische terminologie), zal meer en meer gevoerd worden op het domein van de verwerving van "transversale" deskundigheid om een term te gebruiken die momenteel in zwang is in het opvoedkundig milieu. Deze deskundigheid zal onbetwist en onbetwistbaar moeten zijn. Als radiologen zullen wij in de loop van de volgende jaren geconfronteerd worden met deze uitdaging. Interventieradiologie, specifieke beeldvorming (gynecologie/verloskunde, cardiale beeldvorming, weke delen, enz.) : de radioloog zal zijn positie en zijn plaats slechts kunnen verantwoorden door het bewijs te leveren van zijn essentiële bijdrage op het domein van de diagnostische strategieën, van de algoritmen, van de keuze en van de gelijktijdige overheersing van verschillende technologieën op een zelfde domein (röntgenstralen, echografie, tomodensitometrie, NMR, interventieradiologie). Op die manier zal hij (opnieuw) een centrale positie kunnen innemen als geprivilegieerde gesprekspartner van talrijke correspondenten, zowel huisdokters als specialisten, en van zijn "partners" die actief zijn op dezelfde domeinen (gynecologen, verloskundigen, cardiologen, vasculaire chirurgen, enz.), maar met een meer beperkte technologische aanpak. Hij moet zijn kennis en zijn deskundigheid meer en meer op transversale manier doen uitkomen : om de NMR-beeldvorming van het hart en van de grote bloedvaten te kennen, moet hij natuurlijk ook de fysiologie, de anatomie en de pathologie, de basistechnieken voor beeldvorming, de echocardiografie en de aanverwante technieken

(spiraalscanner, enz.) kennen en bovendien de principes van de radioprotectie beheersen. Voor de andere domeinen van de beeldvorming geldt natuurlijk hetzelfde. Deze gevarieerde deskundigheid (embryologie, foetale anatomie, cardiale pathologie, interventieradiologie, enz.) is trouwens opgenomen in de richtlijnen voor de opleiding voor medische beeldvorming die op Europees niveau voorgesteld worden (AER : EUCORE richtlijnen; zie publikatie in het tijdschrift "Artefact" van april 1996). Sommigen onder de radiologen hebben tijdens hun opleiding echter geen grondige kennis kunnen opdoen over deze begrippen. De Koninklijke Belgische Vereniging voor Radiologie heeft daarom beslist om residentiële cursussen in specifieke beeldvorming te organiseren in de vorm van intensieve lessen gedurende één week. Behalve de cursus in beeldvorming voor GynecologieVerloskunde, zijn reeds cursussen voorzien in cardiovasculaire beeldvorming (hart en grote thoracale bloedvaten), en in beeldvorming voor weke delen. In het begin van 1997 zal inderdaad een week met Inleiding tot de Cardiale Beeldvorming doorgaan, en in 1998 een week over de Beeldvorming van Weke Delen. Op die manier wenst de Koninklijke Belgische Vereniging voor Radiologie - steeds beter haar onderwijsplicht te vervullen, die haar is toegewezen en die ze op buitengewone wijze sinds 90 jaar vervult, met een steeds hernieuwde vitaliteit en geestdrift.

Docteur Jean-Paul JORIS

Voorzitter van de Koninklijke Belgische Vereniging voor Radiologie

LE RADIOLOGUE ET LA PATHOLOGIE GYNECO-OBSTETRICALE F. AVNI

La participation des radiologues dans les mises au point en gynécologie-obstétrique, doit être aussi naturelle que pour les autres spécialités. Ils ne doivent avoir d’appréhension ni pour le type de pathologie, ni pour les techniques à utiliser. Ceci demande bien sûr une bonne connaissance de la pathologie concernée et une utilisation essentielle de l’échographie endovaginale.

En obstétrique, l’intervention d’un radiologue est au départ moins évidente. Le gynécologue

peut

considérer,

probablement

à

juste

titre

que

l’évaluation

échographique de la grossesse est la continuation de l’examen clinique. L’échographie serait l’équivalent du stétoscope. Que peut apporter le radiologue ? En début de grossesse, une connaissance des diagnostics non gynécologiques devant une symptomatologie mal expliquée. Durant les deuxième et troisième trimestres, une meilleure évaluation de l’anatomie foetale grâce à une bonne connaissance tridimentionnelle. Le radiologue peut encore augmenter cette contribution et être encore plus performant s’il améliore ses connaissances en embryologie et en développement foetal. Quant à la pathologie, elle se rapproche beaucoup de celle rencontrée en radiopédiatrie. Enfin le radiologue a, à sa disposition, le plus souvent du matériel plus performant et des sondes échographiques de meilleure définition que le gynécologue. En gynécologie, les choses sont beaucoup plus évidentes. Par sa connaissance de toutes les techniques disponibles et de leur apport respectif, le radiologue peut et doit avoir un rôle central dans les mises au point, pour décider de la meilleure stratégie diagnostique. Il est évident aujourd’hui que l’échographie endovaginale fait partie intégrante de l’arsenal diagnostic et que le radiologue doit l’utiliser. Elle doit entrer dans la logique de toute mise au point gynécologue et être couplée à l’échographie pelvienne transabdominale. C’est une technique facile à réaliser et très informative.

Par ailleurs, pour chaque mise au point le radiologue a l’avantage d’avoir une bonne connaissance de la pathologie non gynécologique, de ce fait, il peut permettre une réorientation de la mise au point dès la découverte d’une anomalie. Il peut donc appliquer en gynécologie des algorythmes décisionnels comme pour les autres systèmes.

A. Les douleurs pelviennes aiguës Principaux diagnostics :

grosssesse extra-utérine endométriome infections torsion d’annexe grossesse (colique néphritique, appendicite...)

Démarche : Echo pelvienne + endovaginale si nécessaire si grossesse  stop si extra-ut  chirurgie si kyste  doppler couleur si endométriome  IRM si abcès/infection  CT si   Echo rénale, FID

B. Douleurs chroniques Principaux diagnostics :

Endométriose varices colopathie

Démarche : Echo pelvienne + Doppler couleur si masse/kyste  IRM si varices  CT si colopathie  LB

C. Masse pelvienne Echo pelvienne + Doppler couleur Masse ovarienne : kyste simple  stop kyste complexe  CT ou IRM fibrome pediculé  stop Masse utérine :

fibrome  stop

Masse extragynécologique :  CT/LB

D. Ménométrorragies Principaux diagnostics :

hyperplasie endométriale adénomyose polype fibrome néo col/endomètre

Démarche : Echo pelvienne polype  HSG adénomyose  HSG ou IRM hyperplasie  HSG néo endomètre  IRM néo col  IRM

E. Stérilité Principales causes : malformation séquelles d’infection synéchies myome

Démarche : échographie pelvienne malformation  IRM OU HSG infection  HSG synéchie  HSG

F. Pré ou post-op néoplasie - Ovaires :

* post-op banal : écho pelvienne écho hépatique * pré ou post-op anormal : écho pelvienne CT (IRM) pelvis US hépatique CT Abdomen supérieur

- Corps-col utérin * pré-op :

écho pelvis IRM pelvis écho hépatique (+CT?)

* post-op :

IRM pelvis écho hépatique (+CT?)

En conclusion, le radiologue peut et doit jouer le rôle central dans les prises en charge diagnostiques des pathologies gynéco-obstétricales.

REFERENCES

1. Ardaens Y, Renan-Druart C. Apport de l’échographie transvaginale à l’étude du cycle menstruel et de la ménopause. Rev Im Méd 1992;4:803-813

2. Bakkos O, Lundkvist O, Wide L and Bergh T. Us and hormonal description of the normal ovulatory menstrual cycle. Acta Obstet Gynecol Scand 1994;73:790-796

3. Lyons EA, Gratton D, Hamington C. TVS of normal pelvic anatomy. Radiol Clin N Amer 1992;30:663-675

4. Mogaiero G, Sheth S, Hamper UM. Endovaginal. Us of the non gravid uterus. Radiographics 1993;13:969-81

5. Schitter VL, Grant EG. Doppler US of the pelvis. Radio Clin N Amer 1992;30:735-742

6. Atri M, Nazaria S, Aldis AE et al. TVS appearance of endometrial abnomalities. Radiographics 1994;14:483-92

7. Arger PH. TVS in postmenopausal patients. Radiol Clin A Amer 1992;30:759-67

8. Taipale P, Tarjanne H, Heinonen UM. Diagnostic value of TVS in the diagnosis of endometrial malignancy in women with peri and postmenopausal bleeding. Acta Obstet Gynecol 1994;73:819-23

9. Kupesic S, Kurjak A et al. The value of TV color doppler in the assessment of pelvic inflammatory disease. Ultrasound Med Biol 1995;21:733-38

10. Buy JN, Ghossain MA et al. Characterization of adnexal masses. AJR 1996;166:385-93

11. Foshager MC and Walsch JW. CT anatomy of the female pelvis : a second look. Radiographics 1994;14:51-66

12. Sutton CL, McKinney CD et al. Ovarian masses revisited : radiologic and pathologic correlation. Radiographics 1992;12:853-77

13. Walsch JW. CT of gynecologic neoplasms. Radiol Clin N Amer 1992;30:817-30

14. Russell AH, Anderson M et al. The integration of CT and MRI in treatment planning for gynecologic cancer. Clin Obstet Gynecol 1992;35:55-72

15. Collins JI, Woodward PJ. Radiological evaluation of fertility. Sem Ultrasound CT/MRI 1995;16:304-16

16. Woodward PJ, Wagner BJ, Fartery TE. MRI in the evaluation of female infertility. Radiographics 1993;13:293-310

17. Olson MC, Posniak HV et al. MRI of the female pelvic region. Radiographics 1992;12:445-65

18. Hricak H. MRI in gynecologic oncology. Eur Radiol 1993;3:1-11

19. Park JM, Chain Dangavery C et al. Pathways of nodal metastasis from pelvic tumors : CT demonstration. Radiographics 1994;14:1309-21

20. Occhipinti KA, Frankel SD, Hricak H. The ovary : CT and MRI. Radiol Clin N Amer 1993;31:1115-1130

NORMAL PELVIC ANATOMY S.Gryspeerdt, L.Van Hoe

The uterus consists of a uterine body, uterine isthmus, and uterine cervix. The junction between the uterine body and the cervix is demarcated by the internal cervical os internally, and by the peritoneal reflection anteriorly from the uterus to the bladder (vesicle uterine ligament). The normal anatomy of the uterus and cervix will be discussed seperately. Since normal anatomy is best demonstrated on MRI images, normal anatomy will mostly be discussed as seen on MRI images.

UTERINE CORPUS At MR imaging, the corpus uteri is characterized by a relatively low signal intensity on T1- weighted MR images. On T2- weighted images, the high-signal-intesity endometrium can be distinguished from the myometrium, which has an intermediate signal intesity. On these images, the two layers are separated by a hypointense band, the so-called junctional zone, for which there is no clear histomorphologic correlate. The appearance of these zone on MR images is accounted for by the reduced water content of the inner portion of the myometrium, which is assumed to attenuate the signal. The size of the endometrium varies during the menstrual cycle. During the follicular phase , endometrial width typically is 1-3 mm. The endometrial zone is widest during the middle of the secretory phase when it usually measures 5-7mm, but may increase 10mm. On MRI , myometrial signal intensity varies during the menstrual cycle, and is maximal during the secretory phase. After intraveneous administration of Gd-DTPA, the inner layer of the myometrium of the premenopausal corpus uteri demonstrates early strong enhancement and the endometrium late moderate enhancement on dynamic sequences, while the junctional zone shows markedly less enhancement. This results in the characteristic zonal anatomy of the uterus as it is also seen on T2weighted images. In the postmenopausal uterus, these 3 zones are no longer discernible on T2weighted images. Rather, the myometrium is characterized by a homogeneous signal intensity, which is lower than that of the premenopausal uterus. The postmenopausal endometrium has a maximal thickness of 3-5 mm.

CERVIX

The cervix can be divided in a vaginal part, which projects into the anterior wall of the vagina, and a supravaginal part. The supravaginal cervix is seperated anteriorly from the bladder by cellular connective tissue: the parametrium. The posterior surface of the supravaginal cervix is covered with peritoneum, which continues onto the posterior vaginal wall and then is reflected onto the rectum, forming the recto-uterine pouch. The junction of the supravaginal and intravaginal portions of the cervix are best shown on sagittal T2 weighted images.These images distinctly show the attachment of the vagina to the cervix. The anterior

and posterior fornices are clearly visible in these images, with the lateral vaginal fornices best shown on axial T2 weighted images. The cervix is primarily a hypointense structure on T1-weighted images, with its internal anatomy being best demonstrated on T2-weighted images. On the latter, a central high signal intensity stripe represents the canal which contains mucous. A slightly lower signal intensity zone, only visible with high resolution scans, may represent the fimbriae palmatae; however; no histologic studies are available to date. A markedly hypointense zone represents the fibrous stroma, which is continuous with the junctional zone of the corpus. An outermost layer, which is of typically moderate signal intensity, and is continuous with the myometrium, also can be seen. Histologic studies have shown this to be part of the fibrous stroma but having a lower cellular count. On CT scans, the cervix/ corpus junction is discernible at the isthmus of the organ. The cervix appears as a roundish to transverse oval structure with a maximum diameter of 3 cm. The cervix or cervical canal is occasionally seen as a central hypointense zone.

VAGINA

The vagina is a fibromuscular tube, which lies between the vestible (cleft between the labia minora), and the uterus. The urethra and bladder lie anteriorly, and the anal canal and rectum lie posteriorly. Cephalically, the vagina surrounds the vaginal portion of the cervix, thereby creating recesses termed the anterior , posterior, and lateral fornices. The vagina is typically divided into thirds. The anatomic distinction between the lower and upper thirds of the vagina is easily seen on transverse images. The lower third of the vagina corresponds to a plain of section below the base of the bladder. Its anatomic level is marked by the anteriorly placed urethra. The middle third of the vagina corresponds to the level of the bladder base. The upper third of the vagina is demarcated by the lateral vaginal fornices. The average length of the vagina is 7 cm. The posterior wall is slightly longer, as its attachment is more superior on the posterior aspect of the cervix. The posterior vaginal fornix is therefore usually deeper than the anterior vaginal fornix. On T1 weighted MR images, the vagina has low signal intensity, which provides excellent contrast between it and the surrounding fat. On T2 weighted images, two zones are identified: a high-intensity center, representing the vaginal epithelium and mucus, and a lower-intensity wall. The hormonal status of the patient affects the size of the vagina, the thickness of the central portion, and the signal intensity characteristics of the vaginal wall. Signal intensity characteristics of the vaginal wall reflects water content, which is dependent on hormonal stimulation. During pregnancy and the middle of the secretory phase of the emenstrual cycle,

the signal intensity of the vaginal wall increases. Low signal intensity is demonstrated during the early proliferative and late secretory phase.

OVARY

The ovaries are normally oval structures that range in size according to the age of the patient. Because ovaries vary in shape, ovarian volume has been considered the most accurate method for determining ovarian size. Ovarian size in adult menstruant has a mean ovarian volume of 9,8 cm3 +/- 5,8. In girls, ovarian volume is generally less than 1 cm3 until about 5 years of age, when the ovary gradually increases in size until menarche , at which time the mean volume is 4,2 cm3. The ovaries are located on each side of the pelvis in a recess called the ovarian fossa, which is bounded anteriorly by the obliterated umbilical artery, and posteriorly by the ureter and internal iliac artery. The ampulla of the fallopian tube arcs over the lateral aspect of the ovary. Each ovary is attached to the posterosuperior aspect of the broad ligament of the uterus, being suspended from the posterior layer by a fold of peritoneum called the mesovarium, through which branches of the ovarian vessels pass to and from the ovary. The lymphatic vessels of the ovary join those from the ipsilateral fallopian tube and fundus of the uteus and ascend with the ovarian vein to lymph nodes located at the level of the renal hilum. Tumor mestases can occur via this lymphatic route. Although there are sometimes difficulties in imaging the ovaries, normal ovaries are demonstrated on MR in 87% of women of reproductive age when continuous slices without gap are used and when the plane of imaging is either coronal or transverse.

Pelvic ligaments. A total of eigt ligaments hold the uterus in place. The broad ligament is formed by two layers of peritoneum and extends laterally from the uterus to the pelvic side wall. Its superior freehand is formed by the fallopian tube medially and the suspensory ligament of the ovary laterally. The lower margin of the broad ligament ends at the cardinal ligament. Between the two leaves of the broad ligament is loose extraperitoneal connective tissue, smooth muscle, and fat, known as the parametrium, which contains the fallopain tube, round ligament, ovarian ligament, uterine and ovarian blood vessels, nerves, lymphatic vessels, mesonephric remnants, and a portion of the ureter. The cardinal ligament (transverse cervical ligament, Mackenrodt ligament) forms the base of the broad ligament and provides the primary ligamentous support for the uterus and upper vagina. It is seen as a triangular soft tissue structure with the base of the triangle abutting the cervix and the apex tapering toward the pelvic side wall. The round ligament attaches to the anterolateral uterine fundus and is positioned in a curved course within the broad ligament to enter the internal inguinal ring. It is seen as a thin soft tissue band.

The uterosacral ligaments extend posteriorly from the lateral cervix and vagina to the sacral body .

Four ligaments support the ovaries. The suspensory ligament of the ovary extends from the ovary anterolaterally, from the external iliac vessels to fuse with connective tissue over the psoas muscle. This ligament is rarely visible. The ovarian ligament (round ligament of the ovary) extends medially from the ovary to the uterus, just inferior and posterior to the fallopian tubes and round ligaments. Its position varies with the ovaries.

Vascular supply to the pelvic organs.

The paired uterine arteries provide the primary blood supply to the uterus. The uterine artery arises from the anterior division of the internal iliac (hypogastric) artery. It courses slightly forward and medialward on the superior fascia of the levator ani muscle to the lower margin of the broad ligament. The uterine artery divides and sends a smaller cervicovaginal branch inferior to the vagina and lower cervix, and a larger uterine branch superior to the uterus. Each of these branches is tortuous and forms extensive vascular networks.

Venous drainage occurs via extensive plexus, mainly lying within the broad ligament. This plexus eventually forms veins that parallell the arterial blood supply. The left ovarian vein however drains into the left renal vein, instead of the inferior vena cava.

Peritoneal and retroperitoneal spaces The pelvic peritoneal spaces can be subdivided into anterior and posterior paravesical spaces. Anterior paravesical spaces are subdivided into the left and right paravesical spaces. The paravesical space is formed by the reflection of the peritoneum from the lateral wall of the bladder into the lateral pelvic wall. This depression reaches laterally and posteriorly to the round ligament of the uterus. Each paravesical space is further subdivided by the umbilical folds (medial and lateral) into supravesical space, medial and lateral inguinal fossa. The anterior intraperitoneal paravesical spaces may be occupied by hollow viscera, ascites, abscesses, or peritoneally disseminated metastases. Occasionally, the ovaries, the ampullary portions of the falloppian tubes, or both lie within the supravesical space. In such cases, ovarian masses may be found in the supravesical space. Posterior paravesical spaces are subdivided into vesicouterine space, rectouterine pouch, ovarian fossae and pararectal fossae. The rectouterine pouch is bounded anteriorly by the broad ligaments, and extends lateral to the rectum. The anterolateral portion of this extension is the ovarian fossa. The ovarian fossa is thus located posterior to the lateral edges of the broad ligaments and anterior to the ureters and internal iliac vessels. In this way, both ureters and internal iliac vessels may serve as a landmark to find the ovaries. The posterior extensions of the rectouterine pouch along the lateral aspect of the rectum are the pararectal fossae.

The pelvic extraperitoneal spaces can be subdivided into the prevesical, perivesical and perirectal space. While the uterus is largely covered by peritoneum, the cervix and vagina are located within the perivesical space. The perivesical space by itself is surrounded by the prevesical space which is continuous with the properitoneal fat and the rectus sheet. Both spaces are seen as fat- containing structures. The immediate retropubic portion of the previsical space is known as the space of Retzius. This space consists of loose areolar tissue, and may contain a large amount of fluid.

Pelvic lymph nodes Pelvic lymph nodes can be divided in common iliac lymph nodes, external iliac lymph nodes and internal iliac lymph nodes. The external iliac nodes consist of three chains: the lateral, the middle and the medial. The internal iliac nodes accompany the visceral branches of the internal iliac artery such as the uterine artery, the gluteal and the internal pudendal artery. The most cephalic internal iliac lymph node which is located below the iliac bifurcation and just below the sacro-iliac joint is also called the hypogastric lymph node. The internal iliac group drains lymph from most of the pelvic organs. Presacral lymph nodes are part of the internal iliac group and can be involved in patients with cervical tumors in case of spread through the uterosacral ligament. Irrespective of the technique used, differentiation between small lymphnodes and other structures such as tortuous vessels and nerves can be difficult. Especially the left common iliac vein might be significantly larger than the right and should not be mistaken for enlarged lymph nodes.

Pelvic floor The levator ani and coccygeus muscles form the pelvic diafragm, extend from the lateral pelvic walls downward and medially to fuse with each other, and are inserted into the terminal portions of the urethra , vagina and anus. Anteriorly, they fail to meet in the midline just behind the pubic symphysis, exposing a gap in the pelvic floor which is completed by the urogenital diaphragm. In this area the inferior area of the pelvic diaphragm fuses with the superior fascia of the urogenital diaphragm. The levator

ani muscle, is subdivided into a larger anteromedial pubococcygeus, and a smaller

posterolateral iliococcygeus portion. The pubococcygeus muscle is seen as a thick muscle that arises from the pubic bones on either side of the midline and passes behind the rectum forming a slinglike arrangement. The ileococcygeneus muscle arises on the pelvic wall and forms a relatively horizontal sheet that spends the opening within the pelvis. The levator ani muscle is the medial boundary of the triangular ishiorectal fossa, which is bounded laterally by the ischiopubic rami and posteriorly by the gluteus maximus muscle. The urogenital diaphragm is depicted as a soft tissue structure between the ischiopubic remy. The central portion of the perineum is seen as a soft tissue structure between the vagina and the rectum. Aside from the muscles of the pelvic diaphragm, two muscles -the obturator internus and the piriformiscover the walls of the true pelvis.The piriformis is triangular and lies flattened against the posterior wall

of the pelvis minor. It originates from three or more processes lateral to the first, second, third and fourth anterior sacral foramina and leaves the pelvis through the greater sciatic foramen above the ishial spine to be inserted by a rounded tendon into the upper border of the greater trochanter of the femur. The obturator internus are fan-shaped and cover the side walls of the pelvis. On axial images, the piriformis muscle appears as a thin band, while the obturator internus is clearly identifiable as the muscle covering the lateral wall of the pelvis. On coronal views, the bulk of the medial part of piriformis muscle and the obturator muscle are evident. The superficial transverse perineal muscles and the bulbo cavernous muscles although small can also be demonstrated.

Developmental anomalies of the uterus. MR imaging should be used in patients with suspected congenital anomalies from whom the results of either US or hysterosalpingographic studies are inclusive and the precise diagnosis is required for treatment. MR imaging is especially indicated in those patients in whom surgical unification of the uterus is anticipated. US has recently been advocated in combination with hysterosalpingography to increase the accuracy of differentiation between bicornuate and septate uteri. However, this technique has limitations in distinguishing septate uteri from bicornuate uterus or a leiomyoma. MR imaging is capable of directly demonstrating the uterus both with its external configuration and internal zonal appearances. Moreover,MR imaging is excellent for delineation of septa because its signal intensity characteristics permit differentiation between myometrium ( bicornuate uterus) and fibrosis ( septate uterus). In septate uterus, an almost normal external configuration with a normal intra- cornual distance will be identified, and a septum consisting of fibrous tissue will exhibit a low signal intensity on T2- weighted images. In a bicornuate uterus, a bilaterally pointed fundus with widened intercornual distance can be seen, and a septum consisting of myometrium has a relatively high signal intensity on T2-weighted images. The differentiation between a bicornuate uterus and a uterus by septus is very important for a bicornuate uterus requires open-surgical repair, whereas in the uterus biseptus a correction can be performed by hysteroscopic metroplasty.

I. GYNAECOLOGY

1. Physiology of ovaries and uterus E. GOES

The female hormonal system The female hormonal system consists of three different hierarchies of hormones : 1) The hypothalamic releasing factors : follicle stimulating hormone releasing factor (FRF) and luteinizing hormone releasing factor (LRF). 2) The anterior pituitary hormones : follicle stimulating hormone (FSH) and luteinizing hormone (LH), which are released in response to the above mentioned releasing factors. The sexual cycle is completely dependent on these gonadotropic hormones. Ovaries that are not stimulated by them remain completely inactive, which is essentially the case throughout childhood. However, at the age of about eight, the pituitary begins secreting progressively more and more gonadotropic hormones, which culminates in the initiation of monthly sexual cycles. During each month there is a cyclic increase and decrease of FSH and LH, causing cyclic ovarian changes. 3)The ovarian hormones: estrogen and progesterone, which are secreted by the ovaries in response to the two hormones of the pituitary gland. Follicular growth The first stage of follicular growth is enlargement of the ovum itself. This occurs at puberty, when FSH from the anterior pituitary gland begins to be secreted in large quantity. Additional layers of granulosa cells develop around each ovum, and several layers of theca cells develop around the granulosa cells. The theca cells originate from the stroma of the ovary and soon take an epithelioid aspect. There total mass is called the theca interna. This layer will secrete most of the female hormones. Surrounding the theca interna, a connective tissue capsule develops, known as the theca externa. At the beginning of each month of the female cycle, approximately at the onset of menstruation, the concentration of FSH and LH increase. This cause an accelerated growth of the theca and granulosa cells in about 20 of the ovarian follicles each month. The theca cells and the granulosa cells secrete a follicular fluid that contains a high concentration of estrogen. This accelerating growth and increasing secretion is caused by two other factors in addition to FSH: -a small amount of LH, also secreted by the anterior pituitary gland, acts synergistically -the estrogen secreted into the follicle acts also synergistically Atresia of all follicles but one dominant After a week or more of growth, but before ovulation, one of the follicles begin to outgrow all the others. This dominant follicle can ultrasonographically be recognised as the one measuring more than 10mm average diameter. The remainder begin to involute (atresia). The cause of atresia is unknown, but it has been postulated that the

one follicle that continues to develop secretes enough estrogen to cause feed-back inhibition of FSH. The lack of this hormone does not prevent further growth of the dominant follicle because the large amount of locally secreted estrogen in this follicle is already causing the continuing growth. However, the lack of FSH stimulus to the less well developed follicles causes these to stop growing and to involute. Ovulation LH is necessary for final follicular growth and ovulation. Without LH, even in the presence of a large amount of FSH, ovulation will not occur. Approximately two days before ovulation the secretion of LH increases markedly, peaking about 18 hours before ovulation. FSH also increases at this moment, and the two hormones act synergistically to cause extremely rapid swelling of the follicle shortly before ovulation. The mature follicle is now seen as a cystic structure of 16 to 25mm average diameter. LH also changes the theca and granulosa cells into lutein cells, that in turn secrete progesterone and less estrogen. This luteinizing process of the theca and granulosa cells is accompanied by growth of new blood vessels (angiogenesis) into the follicle wall. This process can be visualised by duplex ultrasound just before the ovulation. The corpus luteum The theca and granulosa cells undergo a process, called luteinization, and the remaining structure becomes the corpus luteum. This can be smaller, or a little larger, or as large as the previous follicle. On ultrasound, it is visualised as a hyperreflective, heterogeneous (due to internal hemorrhaghe) or anechogenic (cystic corpus luteum). A well developed vascular supply grows into the corpus luteum, due to angiogenesis. The lutein cells start to secrete large amounts of progesterone and estrogen. The vascular supply enables the corpus luteum to fulfil its task of hormone producing organ, and is visible on duplex ultrasound of each active corpus luteum. Even in the absence of further secretion of LH, the corpus luteum will act in this way. However, in the presence of LH its growth is enhanced, its secretion greater, and its life extended. The end of the ovarian cycle (without pregnancy) The estrogen and the progesterone secreted by the corpus luteum causes a negative feedback in the secretion of FSH and LH. The corpus luteum degenerates after 12 days. FSH will start to be secreted again, as well as a moderate amount of LH in order to start the next cycle. The paucity of progesterone and estrogen will lead to menstruation.

The uterus Associated with the cyclic changes in the ovaries, and under the influence of estrogen and progesterone, an endometrial cycle exists, operating through 3 stages : -proliferative phase (estrogen phase or follicular phase) After the menses, only a thin layer of endometrial stroma remains. Under the influence of estrogen, the endometrium grows and becomes more reflective on ultrasound. -secretory phase (progestagen phase or luteal phase) During this phase estrogen and progestagene are produced by the corpus luteum. The estrogen cause additional cellular growth in the endometrium, and progesterone causes secretory development of the endometrial glands. The endometrium becomes more and more reflective, due to the many interfaces in the large tortuous glands, filled with mucin. The inner face of the endometrium may become hyporeflective. Each face of the endometrium has finally a thickness of about 6mm to 8mm. -menses At the end of the monthly cycle, the ovarian hormones decrease sharply, causing menses. Normally, the menstrual fluid is nonclotting, because a fibrolysin is released with the necrotic material. If excessive bleeding occurs from the uterine surface, the quantity of fybrolysine may not be sufficient to prevent clotting. The presence of clots during menses is thus a clinical evidence of uterine pathology. Normally, the ovarian and uterine phases are synchroneus, which can easily been verified by ultrasound. Anovulatory cycles Ovulation will not occur if the LH sure is not important enough. The cycle is then said to be anovulatory. Lack of ovulation prevents the development of the corpus luteum, and thus the secretion of progesterone during that cycle. The cycle will be shortened by several days, but the normal rhythm will continue. During the first few cycles of the puberty, and several years prior to the menopause, anovulatory cycles are usual. The menopause At an average age of about 45 to 50 years, almost all ova of the ovaries are either degenerated or ovulated. Only a few follicles remain to be stimulated by FSH, causing an estrogen production which is too low to inhibit the production of FSH and LH to cause oscillatory cycles. FSH and LH will thus be produced in large, continuous quantities. As the remaining follicles also become atretic, the production of estrogens by the ovaries approaches zero. Due to the lack of progesterone and especially the lack of estrogen the endometrium will become atrophic. The ultrasound aspect will be as just after menstruation: a thin

reflective line , measuring usually not more than 5mm (we usually measure the two endometrial faces together). Endometriosis Endometriosis is the growth and development of endometrial tissue in the peritoneal cavity. This endometrium follows the ovarian cycle in the same manner as uterine endometrium does. However, since hemorrhagic blood cannot be expelled, the quantity of endometrial tissue in the peritoneal cavity progressively increases. This can cause considerable irritation and therefore severe pain. Fibrosis occurs in the areas of endometriosis, causing adhesions and subsequently infertility.

2. Pathology of the female pelvis: anatomo-pathological review.

S.Gryspeerdt, L.Van Hoe

Introduction Gynecologic disorders can grossly be divided into adnexal and uterine pathology. The adnexa encompasses the region within the pelvis that includes the ovary, fallopian tube, round ligament, and structures arising from associated embryologic rests. Uterine pathology includes pathology assigned to the uterine corpus or cervix. Pathological, ovarian masses are non-neoplastic (ovarian functional cysts, endometriomas, polycysic ovary disease, and ovarian torsion) or neoplastic (surface epithelial, sex cord-stromal, germ cell, and metastatic tumors). Tubal masses include tubo-ovarian abcesses, fallopian tube carcinomas, ectopic pregnancy, hydro- and pyosalpinx. Embryologic rests are mostly benign cystic lesions. Uterine pathology includes benign (leiomyoma, adenomyosis, endometrial polyp, and Nahbothian cysts) and malignant disorders ( cervical carcinoma and endometrial carcinoma). Many of all these pathologic entities may have a similar radiologic appearance, and it is therefore frequently impossible for the radiologist to provide the referral clinician with a definite pathological diagnosis. However, understanding the anatomopathological changes allows the radiologist to refine the differential diagnoses and in a few cases allows a specific diagnosis. Therefore, the purpose of this article is to provide a radiologic and pathologic correlation of different gynaecological disorders.

OVARIAN MASSES NON-NEOPLASTIC OVARIAN MASSES 1/ Follicular cysts Follicular cysts are often found incidentally in asymptomatic patients of reproductive age, and range 1-20 cm3 in size. Typically, the cysts are 1-2 cm in size but are frequently larger. Large cysts may become palpable and cause pain. The natural course is spontaneous regression. Therefore, follow-up allows a differention from ovarian tumoral pathology. If a patient has a folicular cyst greater than 5cm, careful follow-up is recommended to exclude tumoral pathology (e.g.cystadenoma). 2/ Corpus luteum cysts Corpus luteum cysts may be larger and tend to be more symptomatic than follicular cysts. These cysts are usually unilateral. The cysts are outlined by a rim of yelloworange tissue containing luteinized cells. In the dependent portion, there may be a complicated hemorrhage. Typically, hemorrhagic cysts regress spontaneously at least by 14-16 weeks from the time of their formation. Carefull follow-up may thus also allow differentiating corpus luteum cysts from tumoral pathology. In some patients, however , hormonal therapy is necessary, and leads to a resolution by at least 6 weeks. 3/ Theca lutein cysts Theca lutein cysts occur when hCG levels are abnormally increased, such as in gestational trophoblastic disease and the ovarian hyperstimulation syndrome caused by treatment with infertility drugs. Theca lutein cyst is the largest of the physiologic ovarian cysts and often bilateral and multilocular.

4/ Polycystic ovary disease Polycystic ovary disease is a complex disorder associated with chronic anovulation. Both ovaries are either normal seized or enlarged and contain multiple tiny follicular

cysts. Ovarian volume is normal in 30% of patients. The cysts range between 5-8mm diameter, with more than 5 in each ovary. Enlarged polycystic ovaries in conjunction with obesity, oligomenorrhea, and hirsutism constitutes the Stein-Leventhal syndrome.Patients with this syndrome are at risk for endometrial and possibly breast carcinoma.

5/ Ovarian torsion Ovarian torsion can occur in normal ovaries, but is more commonly associated with ovarian abnormality. Larger ovaries are at risk, especially in masses over 5 cm. Venous as well as arterial occlusion results in haemorhagic infarction. Chronic ovarian torsion may calcify. 6/ Paraovarian cysts An estimated 10% of adnexal masses are paraovarian cysts.These cysts are remnants of the embryonic wolfian duct and mulerian duct. They show no physiologic or hormonal variations. Morphologically, paraovarian cysts are indistinguishable from simple functional cysts.They may also show haemorrhage. The cysts are located between the fallopian tube and hilum of the ovary. Pedunculated cysts, such as the hydatid of Morgagni are laterally located, and are attacted to the fimbria of the oviduct by a slender pedicle.

7/ Endometrioma Endometriomas are well-circumscribed cystic masses with smooth walls, filled with break down of blood products. Macroscopically , endometriomas are indistinguishable from simple haemorrhagic ovarian cysts. Multiplicity is in favour of endometrioma. 8/ Pelvic inflammatory disease Tubo-ovarian abces (pyosalpinx) is associated with pelvic inflammatory disease. Macroscopically, a tubo-ovarian abcess may mimick any other cystic ovarian process. A tubular appearance suggests tubo-ovarian abcess. Although the acute pelvic inflammatory proces may resolve, reinfection may occur, resulting in scarring of the fallopian tube ostia and subsequent adherence of the ovary. Serous-like fluid collects within the tube, creating a cystic mass called hydrosalpinx. Hydrosaplinx can easily be mistaken for an adnexal cyst.

OVARIAN NEOPLASMS Introduction. Tumors of the ovary arise from one of the three ovarian components: (a) surface coelomic epithelium (b) germ cell line (c) stroma of the ovary. The ovary is also a common site of metastasis. Rarely , lymphoma may occur in the ovary. Tumors of the surface epithelium account for 70-75% of all ovarian tumors, and 95% of malignant ovarian neoplasms.They include serous tumors , mucinous tumors , endometrioid carcinoma, clear cell and anaplastic carcinoma. Germ cell tumors constitute 15-20% of all ovarian tumors, and 1% of all malignant ovarian tumors. They include benign teratoma, dysgerminoma, and endodermal sinus tumor. Sex cord-stromal tumors account for 10% of all ovarian tumors, and 2% of all malignant ovarian tumors.T hey include granulosa and theca cell tumors on one hand, and fibroma on the other hand. Finallly , metastatic tumors account for 5% of all ovarian neoplasms.

TUMORS OF SURFACE EPITHELIUM These tumors are so designated because most of them are considered to be derived ultimately from the surface (coelomic) epithelium (mesothelium) and the adjacent ovarian stroma. They account for about 2/3 of all ovarian tumors and their malignant forms, for over 85% of all ovarian cancers. The common epithelial tumors are subclassified according to four major characteristics: (1) their epithelial cell type(s) (2) their degree of malignancy (benign, borderline -or low malignant potential-, an dmalignan) (3) the relative amounts of epithelial and stromal components they contain, and (4) the locus of growth of their epithelial elements: surface (exophytic), cystic (endophytic), or both. The five epithelial cell types are the serous, the mucinous, the clear cell, endometrioid, and Brenner. 1/Serous and 2/mucinous tumors Serous tumors account for 20 to 50% of all ovarian tumors, and their benign forms for a similar proportion of benign ovarian neoplasms. Of all serous tumors, approximately 70% are benign, 5 to 10% are of borderline malignancy, and 20 to 25% are carcinomas. Benign serous tumors may occur at any age, but are most common in the reproductive age group, particularly during the third and fourth decades. The

borderline tumors are encountered during the ages 30 and 60 years, and the carcinomas with invasion between the ages of 40 to 70 years. Serous tumors usually do not attain the size of their mucinous counterpart. Serous tumours often are loculated and are characterized by papillary excrencies on the inner surface of the cysts. The inner wall is otherwise smooth. Although the presence if the excrescences increases the suspicion of malignancy, their occurance is not unusual in benign cystadenomas. Psammoma bodies are found in serous cystadenocarcinomas, and may calcify. Peritoneal metastasis from serous cystadenocarcinoma may also contain psammaomatous calcifications, allowing specific radiologic diagnosis of peritoneal implants from serous cystadenocarcinoma. Mucinous tumors account for 15 to 25 % of all ovarian tumors.The cystadenomas make up a similar portion of all benign ovarian neoplasms, and mucinous carcinomas account for 6 to 10% of all ovarian cancers. Of all ovarian mucinous tumors, 85% are benign, 6 % borderline, and 9% invasive. Mucinous tumors may occur at any age, but are most frequent during the third through fifth decades; the borderline and invasive mucinous tumors occur at a slightly older age, most often during the fourth through seventh decades. Mucinous tumors tend to be the largest ovarian neoplasms. The capsule usually is smooth, while the internal component is multiloculated by multiple septae. Cellular elements that comprise these tumors are rich in mucin ; cystic contents therefore are thick and gelatinous. Papillary excrencies are less common in mucinous tumors than in serous tumors. Most important is however, not to differentiate the serous from mucinous neoplasms, but to differentiate cystadenomas from cystadenocarcinomas. The following macroscopic features are in favour for benign adnexal lesion: (a) size less than 4cm (b) entirely cystic structure (c) wall thickness less than 3mm. There is however a considerable overlap with malignant disease, since large, benign lesions are common, and solid components may be found in benign as well as malignant disease. Borderline tumors frequently present as cysts with endocystic vegetations. Calcifications are found in serous cystadenocarcinomas (psammomatous calcifications). CLINICAL COURSE Benign serous tumors have a favourable clinical course. However, their occurance at a younger age than that of patients with borderline or malignant serous tumors suggests possible malignant degeneration.

Borderline or malignant serous tumors are often associated with peritoneal spread. Lymph node metastasis and pleuropulmonary involvement is frequent, especially in the late stages of the disease. Benign and borderline mucinous tumors have a favourable clinical course, but may on occasion be associated by large amounts of mucinous fluid in the peritoneal cavity, referred to as pseudomyxoma peritonei. Mucinous carcinomas may also be complicated by pseudomyxoma peritonei, but tend to remain confined to the ovary for a longer period than their serous counterparts. In the later stages of the disease, lymphatic and hematogeneous spread may occur. N.B.In most cases of pseudomyxoma peritonei that are associated with ovarian tumors, a "mucocoele" of the appendix is found at surgery.

3/ Clear cell carcinomas Clear cell carcinomas account for 5% of all ovarian cancers. They occur most frequently between the ages of 40 and 70 years, but have been seen in older and younger adults and, rarely in children. Most clear cell carcinomas are predominantly cystic. The most common appearance is that of an unilocular cyst with one or more solid nodules, protruding into its lumen.

CLINICAL COURSE Clear cell carcinomas tend to be confined to the ovary and the pelvis. Extra-abdominal spread is unusual. 4/ Endometrioid carcinomas Endometrioid carcinomas account 15 to 25% of all ovarian malignant neoplasms.They occur primarily in the fifth and sxth decades, but are occasionally encountered in older women and less often at a younger age. Endometrioid carcinomas may ocur in preexisting endometriomas. On gross examination, these tumors are predominantly cystic. Soft papillae or firm, solid masses may protrude into the lumen of the cysts, which may contain cholocate fluid or mucus. Endometrioid carcinomas are bilateral in approximal 30% of cases.

CLINICAL COURSE Endometrioid carcinoma tends to remain confined to the ovary and pelvis. Fifteen to twenty percent of the endometrioid carcinomas of the ovary are associated with carcinoma of the endometrium, which is usually identical with the pattern and grade of the tumor of the ovary. The fact that the coexistence of both tumors does not worse the prognosis of the patient, the small size of many of the accompanying endometrial tumors and the occasional association of the latter with precancerous changes elsewhere suggests that the combination of both reflects a multicentric origin rather than a tumoral spread from one organ to another.

5/ Brenner tumors (transitional cell tumors) Brenner tumors are characterised by nests and colums of epithelial cells, most of which are of transitional type, resembling the epithelial lining cells of the urinary bladder. These tumors account for 2 to 3 % of all ovarian tumors. Most Brenner tumors are benign , and have been found in fourth through eigth decades with a peak frequency in late forties and fifties. Most of these tumors are small (< 2cm) solid lesions . The tumor is well circumscribed, composed of hard, fibromatous tissue, and is occasionaly calcified. Although most frequently benign, borderline as well as malignant types have been reported. The benign tumors frequently show a solid component, while the borderline tumors are characteristicaly cystic, and more often multilocular than unilocular. Benign, borderline or maligant Brenner tumors may all have mucinous components. CLINICAL COURSE Benign as well as borderline Brenner tumors have been associated with a benign clinical course. The few reported malignant Brenner tumors were mainly confined to the pelvis, with only few cases with reported distant metastasis. 6/ Mixed epithelial tumors Mixed epithelial tumors are composed of two or more of the five major types of common epithelial tumor. The tumor is called mixed when at least 10% of the tumor is compound by the second component.

Peritoneal adenocarcinomatosis Peritoneal adenocarcinomatosis is histologically indistinguishable from ovarian carcinomas, but found in the abscence of macroscopically identifiable ovarian disease. They are termed primary peritoneal adenocarcinomas or surface papillary carcinomas. The minimal ovarian involvement of these tumors make them difficult to recognise radiologically.

GERM CELL TUMORS Germ cell tumors constitute 30% of all ovarian tumors; 95% of all germ cell tumors are benign dermoid cysts. The remainder have a higher frequency of malignant behavior and arise largely in children and young adults. Germ cell tumors include dysgerminomas, teratoma, endodermal sinus tumors, choriocarcinoma, embryonal carcinoma, and mixed germ cell tumors.

1/ Teratomas Teratomas contain several types of tissue that recapitulate the development of two or three of the embryonal layer (endoderm, mesoderm, ectoderm). Teratomas are divided into three main categories: (a) mature (benign), (b) immature (malignant), (c) highly specialized (monodermal). MATURE (BENIGN) TERATOMAS Benign teratomas are divided into the very rare mature solid and the very frequent mature cystic teratomas. mature cystic teratomas (dermoid cyst) Over 80% of the dermoids occur during the reproductive years. They are however also found in children and post-menopausal women. They account for half of the ovarian neoplasms that appear in the first two decades, and over two-thirds of those in patients under age of 15 years. The dermoid cysts appear as a cystic tumor, usually less than 15 cm. Yellow or brown sebaceous material fills the cyst. Almost always, one or more polypoid masses protrude into the lumen. These masses are referred to as mamillae, nipples, or Rokitansky protuberances. Teeth are present in a third of cases, either in the cyst wall or in the cavity. Bone, cartilageneous material, adipose tissue and soft brain tissue are other frequently encountered compounts. Because the sebaceous content of the cyst typically forms a rounded or ovoid mass of abnormally low density surrounded by a ring of increased capsular density, and calcified structures, a specific radiologic diagnosis of dermoid cyst can be made in most of the cases. CLINICAL COURSE

Besides producing the more typical signs of benign ovarian neoplasms, dermoid cysts are unusual susceptible to complications: torsion (16%), infection, or perforation may occur. Approximately 1% of the cystic dermoids undergo malignant degeneration of one of the component elements, with the most common transformation being squamous cell carcinoma. It is found most often in teratomas removed from postmenopausal women. mature solid teratomas This form of teratoma is predominantly solid and composed exclusively of mature elements. It appears as a solid lobulated mass, containing numerous small cysts. The solid portion contains cartilage or bone. The cysts contain clear fluid, mucus or sebaceous material and hair. CINICAL COURSE The clinical course is one of slowly growing ovarian tumor.

IMMATURE (MALIGNANT) TERATOMA The immature teratoma is a malignant form of teratoma that contains immature structures resembling those of the embryo. Most malignant teratomas arise in prepubertal adolescents and young women. These tumors are macroscopically identical to the solid mature teratoma. CLINICAL COURSE Besides producing the usual symptoms of ovarian masses, these tumors may cause sexual pseudoprecocity, presumably due to the undetected trophoblastic components. Distant metastasis are rarely observed. MONODERMAL TERATOMAS These rare tumors are teratomas, build up mainly from highly specialized cell types. Two subtypes can be mentioned: struma ovarii and carcinoids. Struma ovarii is a teratoma in which thyroid tissue is present exclusively. These tumors may be solid and firm, but are often partly or predominantly cystic. The mucoid fluid in struma ovarii may result in confusion with mucinous cystadenoma. Carcinoids have microscopic features similar to gastro-intestinal carcinoids. The tumor may appear as a small tan nodule protruding the lumen of dermoid cyst. It may lie within a mature, solid teratoma, or may form a large, predominantly solid, homogeneous, firm, tan mass.

2/ Dysgerminomas Dysgerminomas account for 50% of the malignant germ cell tumors. They are predominantly found in young women (80% < 30 years), and is very rare over the age of fifty. Because of this age distribution, dysgerminomas account for 20 to 30% of tumors detected during pregnancy. The tumor is bilateral in 15-20% of cases. Macroscopically, dysgerminomas present as large solid masses that may range up to 50cm. Cysts may be encountered. CLINICAL COURSE Three fourth of the tumors is confined to the ovary at time of operation. Extention of the tumor is primarily within the abdomen, with relatively high frequency of lymph node metastasis. Dysgerminoma is one of the most radiosensitive human cancers and long-term cure are achievable in many cases despite extraovarian spread that includes distant metastasis.

3/ Endodermal sinus (yolk sac) tumor This tumor is a rare , malignant tumor of germ cell origin, accounting for 20% of malignant germ cell tumors. The tumor is thought to derive from multipotential embryonal carcinoma by differentiation toward yolk sac structures. Yolk sac tumor occurs chiefly in children or young women. The tumors are predominantly solid, but cystic degeneration may occur. Areas of necrosis and haemorrhage are frequently enountered. CLINICAL COURSE Tumor growth is rapid and agressive with poor prognosis.

4/ Embryonal carcinoma 5/ Choriocarcinoma Embryonal carcinoma and choriocarcinoma are both extremely rare germ cell tumors.

The embryonal carcinoma is found in young girls, with a mean age of 15yr; the patients present wit endocrine manifesttations, most often isosexual precocity and menstrual disturbances. Grossly, the tumors are solid, unilateral, extensively necrotic, and hemorhagic. The choriocarcinoma is combined in varying proportions with other forms of malignant germ cell neoplasia, and, thereofore, belongs to the category of mixed germ cell tumors. The tumor is found in patients , usually younger than 20 year. Grossly, the tumor is solid and hemorrhagic. SEX CORD STROMAL TUMORS This category includes all neoplasms that are derived ultimately from the sex cords, or primitive cortical lobules, and the specialized stroma (mesenchyme) of the developing gonad. The elements that may be found in these tumors , singly or in various combinations, include the female-type cells, granulosa cells, and theca cells, either or both of which may be luteinized, the male type cells, Sertoli cells and Leydig cells. Neoplasms in this category which account for approximately 6% of all ovarian tumors, and include the majority of functioning tumors with clinical manifestations, may contain granulosa cells, Sertoli cells, Leydig cells, theca cells, and fibroblasts of gonadal stromal origin, either singly or in any combination and in any degree of differentiation. 1/ Granulosa and theca cell tumor Granulosa and theca cell tumors may be composed entirely of theca cells (thecoma) or entirely of granulosa cell (granulosa cell tumor). They account for less than 10% of ovarian cancers and less than 2% of all ovarian tumors. The tumors are almost never found before puberty, and approximately 66% occur in post-menopausal women. Granulosa cell tumors have a wide range of gross appearances, but most typically, they form a large, multicystic semi-solid mass, with the cysts containing watery fluid, or more typically, containing clotted blood. Areas of haemorhage are often encountered.

CLINICAL COURSE These tumors are interesting from a clinical view-point because of their potentially active hormonal status. Functional active tumors may induce precocious puberty in young girls, whereas endometrial hyperplasia, endometrial carcinoma (10-15%), and cystic diseases of the breast occur in adult patients. Just as clinically important is the fact that these tumors are potentially malignant, although those consisting predominantly of theca cells are almost never malignant. 2/ Androblastomas Sertoli-Leydig cell tumors are characterised by cells that resemble Sertoli and Leydig cells in their cytologic features. They are in reality Sertoli cell tumors, and the Leydig cell component is in fact a nonneoplastic stromal response showing Leydig cell differentiation. Sertoli Leydig cell tumors have the same wide range of gross appearance as granulosatheca cell tumors. CLINICAL COURSE Sertoli-leydig cell tumors typically produce androgens and virilize 70-80 % of patients, who are usually young women with regular menses before the onset of symptoms. Most Sertoli-Leydig cell tumors are of low grade malignancy, but poorly differentiated tumors with rapid fatal outcome have been reported in literature. 3/ Gynandroblastoma Gynandroblastomas are extremely rare ovarian tumors, containing well differentiated male and female cell types.

4/ Thecoma - fibroma fibroma Fibromas are composed of spindle cells forming collagen. They account for 4% of all ovarian tumors, are found at all ages, but predominantly during middle age, with a

mean age of 48 years. They are rare in young patients, except for the basal cell nevus sydrome, in whom the tumors are bilateral, multinodular, and calcified. Macroscopically these tumors present as a solid mass. CLINICAL COURSE The fibroma has a benign clinical course. This is of particular interest in view of the fact that large fibroma (>10 cm) may present with ascites. The occurence of the Meighs syndrome is also exceptionally been reported. thecomas The thecoma is composed predominantly of lipid-rich cells of stromal origin, which bear a resemblence of theca interna cells. The tumor typically occurs in the post-menopausal women. Macroscopically thecomas are solid, lobulated masses. CLINICAL COURSE The thecoma has a benign clinical course and may exceptionally be associated with the Meighs syndrome or ascites.

OTHER RARE OVARIAN NEOPLASMS To complete this anatomopathological review of ovarian pathology, the following tumors are mentioned. Because of their rarity, these tumors are however not discussed. STEROID CELL TUMORS ( LIPID OR LIPOID CELL TUMORS) These are very rare tumors (0,1% of all ovarian tumors) composed exclusivey of large, rounded or polyhedral cells that resemble Leydig , lutein, an adrenal cortical cells, but cannot identified specifically as any of the three.

LEYDIG CELL TUMOR; HILUS CELL TUMOR This tumor s composed exclusively of Leydig cells. NONSPECIFIC AND MISCELLANEOUS TUMORS Most of these tumors belong in the soft tisue category. A wide variety has been described: benign mesenchymal : leiomyoma (e.g. fibroma originating from unspecialized fibroblasts) hemangioma hemangiopericytoma benign neural tumors (ganglioneuroma, neurofibroma) lymphangiomas myxomas osteomas lipoma sarcomas miscellaneous mesotheliomas adenomatoid tumors pheochromocytoma hydatiforme mole

METASTATIC TUMORS Metastatic disease constitutes 5% of all ovarian tumors and originates mainly from four sites: the gastro-intestinal tract (stomach, biliary tract, pancreas, colon), breast, lymphatic tissue, and pelvic region. Metastasis to the ovary also arise from less common primary tumors such as melanoma. If there is massive, bilateral ovarian enlargement due to metastatic lesion, a Krukenberg tumor should be suspected. Krukenberg tumors are defined as an ovarian metastasis containing mucin-filled signet-ring cells, typically lying within a nonneoplastic cellular ovarian stroma. The most common primary source is the gastric carcinoma, followed by carcinomas of the large intestine, appendix, and breast. The galbladder, biliary tract, cervix, and urinary bladder are rare sources. Pathologically these metastatic lesions are typically firm white masses that occasionally may contain large cystic areas in addition to the more solid component.

PATHOLOGY OF THE UTERINE CORPUS

PATHOLOGY OF THE MYOMETRIUM Leiomyoma Leiomyoma is the most common uterine mass. It has an approximate prevalence of 30% to 40% in women who are able to reproduce. Although it often is called a fibroid tumor, the leiomyoma is actually a benign smooth muscle tumor with varying amounts of connective tissue. Leiomyomas originate within the myometrium and can present clinically as an enlarged uterus, menorrhagia, infertility, or a pelvic mass of unknown etiology. In approximately 65% of the cases, secondary changes occur.These include hyaline degeneration (19%), calcification (8%), cystic changes (4%), fatty metamorphosis (3%), and red degeneration (3%). Inflammatory pseudotumors are leiomyomas that are massively infiltrated by lymphocytes, plasma cells, or eosinophils, surrounded by relatively unaffected myometrium. Leiomyomas are classified according to their location within the uterus: submucosal, intramural or subserosal. Submucosal leiomyomas are most commonly symptomatic. These lesions can distort the endometrium, making it unsuitable host to the developing embryo. In addition, these lesions commonly present with uterine bleeding. Intramural leiomyomas are least often symptomatic, but if these lesions become large, they can cause distortion of the endometrial canal that results in infertility. When these lesions occur near the ostium of a fallopian tube, they may cause tubal obstruction. Subserosal leiomyomas rarely cause infertility or uterine bleeding.They may however torse on their pedicles, resulting in infarction and pain. In addition, these lesions may simulate adnexal masses clinically.

Leiomyosarcomas Leiomyosarcomas account for approximately 45 percent of uterine sarcomas. The vast majority is found in patients over 40 years of age. Patients usually present with abnormal vaginal bleeding and pain. Rapid enlargement of leiomyoma suggests

leiomyosarcoma, but it has to be taken into account that leiomyomas in women taken exogeneous hormones may also show rapid growth. Leiomyosarcomas are typically large solitary masses (10cm). Approximately two thirds are intramural, one fifth submucosal, and one tenth subserosal. These tumors are less well circumscribed than leiomyomas, are focally necrotic and may show hemorrhage. Smooth muscle tumors with unusual growth patterns Diffuse leiomyomatosis is a benign disorder, characterised by symmetric uterine enlargement due to the presence of countless, confluent , leiomyomatous nodules within the myometrium. Leiomyoma with vascular invasion is a rare, otherwise typical leiomyoma with microscopically intravascular growth confined to the tumor. Intraveneous leiomyomatosis is an uncommon uterine tumor characterized by the presence of intraveneous proliferations of benign-appearing smooth muscle in the abscence of, or outside the confines of a leiomyoma. The term peritoneal leiomyomas has been applied to otherwise unremarkable, usually solitary leiomyomas, or leiomyoma variants attached to the pelvic peritoneum in women who have usually uterine leiomyomas. The peritoneal tumors in such cases are thought to originate from subserosal pedunculated uterine leiomyomas that become attached to, and vascularised by the pelvic peritoneum, eventually loosing their attachment to the uterus.

Myometrial cysts Excluding adenomyotic cysts (cfr infra), cystic degeneration of myometrial neoplasms, and cystic neoplasms (adenomatoid tumor, lymphangioma), myometrial cysts are rare. Most of them are congenital in origin. The cysts are unilocular, filled with clear fluid, surrounded by myometrium.The majority are of the Mullerian type, and located in the midline of the anterior or posterior uterine wall. Lipomatous uterine tumors. Lipomatous uterine tumors are rare benign neoplasms; just under 100 cases have been reported. The histologic spectrum includes pure lipomas, lipoleiomyomas, and fibromyolipomas. These masses are similar to uterine leiomyomas both in clinical presentation and course. , and may be endophytic or exophytic with repsect to the uterus. PATHOLOGY OF THE JUNCTIONAL ZONE The junctional zone is recognised on magnetic resonance imaging as a low signal layer between endometrium and myometrium. It has been shown that this layer corresponds to the inner most layer of the myometrium. Although no distinct histologic correlate to the junctional zone has been demonstrated, it has been shown that the myometrium within the junctional zone has a higher nuclear-to-cytoplasmatic ratio than the remaining myometrium. The corresponding increase in cellular fracture could explain the low signal intensity on MRI.

Adenomyosis and adenomyomas The histopathologic criterium for adenomyosis is the presence of endometrial tissue within the myometrium at least one x100 microscopic field below the endometrial junction. The adenomyotic foci consists endometrial glands and stroma, surrounded by hyperplastic myometrium. On gross examination, adenomyosis presents as a focally or diffuse thickened, trabeculated myometrium. Blood filled cysts, usually less than 0,5 cm may be seen. Diffuse adenomyosis presents as a widening of the junctional zone (> 12mm) on MRI. High signal foci within the junctional zone on T2 weighted images represent either ectopic endometrial tissue, endometrial cysts, or haemorrhagic foci. When the process forms a discrete, leiomyoma-like mural mass, the designation adenomyoma is used. When a polypoid mass projects into the endometrial cavity, the lesion is referred to as a polypoid adenomyoma. PATHOLOGY OF THE ENDOMETRIUM Endometrial hyperplasia An unknown proportion of endometrial carcinomas are preceeded by precancerous hyperplasia. Pathologically, hyperplasia is divided into four groups : simple hyperplasia, complex hyperplasia, atypical simple hyperplasia, atypical complex hyperplasia. Since these types cannot be distinguished on basis of radiological findings ( distinguishing atypical endometrial hyperplasia from grade 1 endomerial adenocarcinoma is moreover difficult for pathologists), a detailed description is beyond the scope of this article. It is however worthly to be mentioned that MRI cannot reliably distinguish hyperplasia from carcinoma. Widening of the endometrial stripe (more than 1 cm in the premenopausal , and more than 3 mm in the post menopausal women) may indicate early endometrial carcinoma as well as hyperplasia. Endometrial polyps Endometrial polyps are pedunculated lesions that contain hyperplastic endometrial tissue. They most often occur in the region of the uterine fundus, adjacent to the cornua of the uterus. Clinically , patients with polyps present with bleeding. Rarely, the polyp can prolaps through the cervical canal os, causing it to present externally.

Several studies have found that endometrial polyps are a risk factor for endometrial carcinoma.

Pathology of the endometrium treated with tamoxifen. Tamoxifen is an antiestrogen, used in the adjuvant treatment of breast cancer. Although tamoxifen is an anti-estrogen, it may act as weak estrogen agonist in postmenopausal women, depending on the target tissue. In the vaginal and the endometrial epithelium it produces estrogenic change. It may also promote the development of endometrial hyperplasia and endometrial polyps, adenomyosis, and endometriosis, and stimulates the growth of fibroids. Some clinical data imply that tamoxifen may increase the risk of endometrial cancers.

Endometrial carcinoma Grossly, carcinoma of the endometrium forms broad-based polypoid masses or grow diffusely into the myometrium. In general, extensive myometrial invasion is accompanied by clinically detectable uterine enlargement. However, notable exceptions occur; sometimes, deep myometrial invasion is accompanied by a normalsized uterus. At times, the tumor begins in a corum and is missed by curettage. About 80% of the endometrial carcinomas are conventional adenocarcinomas, which are usually divided into well- (grade 1 50%), moderately (grade 2, 35%) and poorly differentiated (grade 3, 15%) tumors. Different histological subtypes have been recognised: endometrioid (80%, the histological changes closely resemble the nonneoplasic endometrium), adenosquamous (5%), serous papillary (5-10%), clear cell (4%), mucinous (rare), squamous (extremely rare), undifferentiated , and mixed (510%).

Endometrial stromal tumors are tumors that are composed of endometrial stroma. These tumors tend to occur in middle-aged women, and often present with vaginal bleeding. They have been divided into (a) a benign category (stromal nodule), and (b) a malignant category (low and high grade stromal sarcomas). Stromal nodules are solitary sharply circumscribed nodules, not invading veins, lymfatics or myometrium, thus having an excellent prognosis. Low and high grade stromal sarcomas invade veins, lymfatics or myometrium to a varying degree.

Malignant mixed Mullerian tumors (syn.:mixed mesodermal tumor, carcinosarcoma) , Mullerian adenosarcoma, and related tumors are rare neoplasms, seen practically always in post-menopausal women. These tumors have a tendency to occur in the uterine body, the most common site for malignant mixed Mullerian tumors being the posterior wall. They typically have a polypoid growth involving the endometrium and the myometrium, sometimes protruding from the cervix; this may cause "over-staging" on MRI. Foci of necrosis and hemorrhage are common.

PATHOLOGY OF CERVIX

NON-NEOPLASTIC DISORDERS Multiple infectious non-neoplastic disorders of the uterine cervix are known. However, since none of these produce radiological indentifiable changes, these infections will not be discussed. Nabothian cyst is the most common benign lesion of the cervix, that can reliably be detected on MRI. Nabothian cysts represent mucus distention of the deep glandular follicles that occupy the upper two thirds of the cervix. They present as 1 to 5 mm, mucus-filled nodules on the inner surface of the cervix. Occasionally, they can be up to 1-2 cm. Endocervical polyps are not true neoplasms but probably the result of chronic inflammatory changes ("chronic polypoid cervicitis"). They usually are small but may reach several centimeters in diameter. The surface of the epithelium usually shows squamous metaplasia. Carcinoma in situ can develop from these polyps but not more so than in the cervix as a whole. TUMORS OF THE CERVIX. Dysplasia, carcinoma in situ (CIN), and microinvasive epidermoid carcinoma can not be identified radiologically and are therefore not discussed. Invasive epidermoid carcinoma is the most common malignant tumor of the gynecologic tract in most countries. Grossly, the tumor may grow out , or infiltrate the cervix. The bulky tumors that grow out the cervix are less likely to invade surrounding structures than are the infiltrating ones.

Adenocarcinoma makes up 5 to 15% of all carcinomas of the cervix. The tumor presents no distinguish gross characteristics. Cervical adenocarcinoma can be poorly differentiated, papillary and with psammoma bodies (thus resemblnig ovarian papillary serous carcinoma), or have an endometrioid appearance. Some of the latter have coexistent endometrioid carcinoma of the ovary. Pathologically, endometrioid carcinoma of the cervix can not be differentiated from endometrioid carcinoma of the endometrium. Tumor involving the cervical canal as well as the uterine corpus on MRI may thus originate in the cervix as well as the endometrial canal. Variants of adenocarcinomas are adenosquamous or mixed carcinoma, glasy cell carcinoma, and adenoid cystic carcinoma. Adenosquamous and glassy cell carcinoma are associated with pregnancy; adenoid cystic carcinoma tends to occur in elderly multigravid black women. Clear cell carcinoma is the most common cervical carcinoma in young patients. Grossly, this tumor is usually exophytic.

APPENDIX : FIGO STAGING SYSTEM FOR OVARIAN, ENDOMETRIAL AND CERVICAL CANCER: FIGO STAGING FOR OVARIAN CARCINOMA STAGE I : GROWTH LIMITED TO THE OVARIES stage Ia GROWTH LIMITED TO ONE OVARY; NO ASCITES 1/ no tumor on the external surface 2/ tumor presentS on the external surface or/and capsule ruptured stage Ib GROWTH LIMITED TO BOTH OVARIES; NO ASCITES 1/ no tumor on the external surface; capsule intact 2/ tumor present on the external surface or/and capsule ruptured stage Ic Tumor aither stage Ia or Ib, but with ascites present or positive peritoneal washings

STAGE II: GROWTH INVOLVING ONE OR BOTH OVARIES, WITH PELVIC EXTENSION stage IIa Extension and/or metastases to the uterus and/or tubes stage IIb Extension to other pelvic tissues stage IIc Tumor either stage IIa or stage IIb, with acsites or positive peritoneal washings STAGE III: Growth involving one or both ovaries with intraperitoneal metastases outside the pelvis and/or positive retroperitoneal nodes Tumor limited to the true pelvis with histologically proved malignant extension to smal bowel or omentum. STAGE IV: Growth involving one or both ovaries with distant metastases. If pleural effusion is present, there must be positive cytology to allow a case to stage IV. Parenchymal liver metastases equals stage IV. SPECIAL CATEGORY Unexplored cases which are thought to be ovarina carcinoma. FIGO STAGING FOR ENDOMETRIAL CARCINOMA

STAGE I: tumor limited to the uterine corpus Ia tumor limited to endometrium Ib invasion to < 1/2 myometrium Ic invasion to > 1/2 myometrium STAGE II: invasion to cervix, but no extent into periuterine tissue IIa endocervical glandular involvement only IIb cervical stromal invasion STAGE III: tumor extends beyond the uterus, but not outside the true pelvis IIIa tumor invades serosa and/or adnexa and/or positive peritoneal cytology IIIb vaginal metastases IIIc metastases to pelvic and/or para-aortic lymph nodes STAGE IV: tumor extends beyond the uterus, and outside the true pelvis IVa tumor invasion of bladder and/or bowel mucosa IVb distant metastases (including intra-abdominal) and/or inguinal lymph metastases

node

FIGO STAGING FOR CERVICAL CARCINOMA STAGE O

Carcinoma in situ

STAGE I Carcinoma confined to the cervix (extension to disregarded) Ia Ib

preclinical carcinoma of stage I disease all other cases of stage I disease

STAGE II Carcinoma extends beyond the cervix, without to the lower third of the vagina or to the pelvic wall. IIa IIb

the corpus

extention

no parametrial involvement parametrial involvement

STAGE III Carcinoma extends to the pelvic wall and/or the lower third of the vagina; all cases of hydronephrosis or non-functioning kidney (unless due to other cause). IIIa IIIb

no extensin to the pelvic wall extention to the pelvic wall and/or hydronephrosis or non-functioning kidney

STAGE IV Carcinoma extends beyond the true pelvis involves the urinary bladder or rectum. IVa IVb

spread to adjacent organs spread to distant organs

or

3. Principles of MRI and application to studies of the female pelvis L. VAN HOE, S GRYSPEERDT

4. Le Doppler couleur endovaginal en pratique gynécologique Y. ARDAENS

5. Echographie pelvienne chez la fille : de la naissance à la puberté Ph. CLAPUYT

1. INTRODUCTION Hormis les organes génitaux, le petit bassin féminin est composé de structures osseuses, urinaires, digestives et nerveuses dont nous ne parlerons pas dans cet exposé. Nous étudierons principalement l’anatomie normale et la pathologie des organes génitaux internes. Nous n’aborderons pas en détail la pathologie tumorale et les problèmes hormonaux qui sont traités dans d’autres exposés, mais nous pointerons quelques caractéristiques propres à l’enfant. 2. TECHNIQUE L’examen du petit bassin chez la fille doit être réalisé avec une vessie suffisamment remplie pour observer convenablement la vagin, l’utérus et les ovaires. Idéalement, un examen post-mictionnel doit être réalisé lors de la suspicion d’une pathologie urinaire basse. Il est indispensable d’utiliser une sonde dont la fréquence est adaptée à la taille de l’enfant : 7.5 mHz voire 10 mHz chez le nourrisson. Les sondes mécaniques sectorielles ou électroniques à contact d’entrée ponctuel doivent être préférées aux barrettes ou sondes à large contact d’entrée. L’accessibilité aux ovaires au travers d’une vessie en semi réplétion est ainsi facilitée. La voie d’abord est essentiellement suspubienne, mais la voie périnéale est une alternative performante en pathologie vaginale et utérine basse, surtout chez le nourrisson et le petit enfant. 3. LE VAGIN 3-1. Les parois vaginales sont épaisses dans la période néo-natale : imprégnation hormonale maternelle. 3-2. Régression de cet aspect au cours des deux premiers mois de vie. 3-3. Présence d’un peu de liquide vaginal de manière physiologique après la miction chez le nourrisson (reflux urinaire banal dans le vagin pendant la miction). 3-4. Visibilité de corps étrangers : tampon menstruel chez la fille pubère mais aussi objets divers introduits par jeu (à rechercher quand « métrorragies » - vaginorragies).

* Cliniques Universitaires St Luc, Département d’imagerie médicale, 10 Avenue Hippocrate, 1200 Bruxelles

3-5. aspects pathologiques 3-5.1 : absence de vagin syndrome de Rokitansky - Kuster - Hauser : ce syndrome associe des anomalies génito-urinaires, des anomalies squellettiques et de manière inconstante une absence d’utérus. 3-5.2 : atrésie vaginale diagnostic différentiel possible avec obstruction congénitale simple du vagin si visualisation d’un septum transversal d’épaisseur supérieure à 7 mm. 3-5.3 : obstruction congénitale du vagin - étiologie : - imperforation hyménéale - fusion des petites lèvres - testicule féminisant - symptomatologie apparente aux deux extrêmes de l’âge pédiatrique - période néonatale : hydrocolpos, hydrométrocolpos ou hématométrocolpos (décharges sanglantes) - période pubertaire : hématométrocolpos - l’échographie montre une masse liquidienne ou à contenu mitigé, médiane, limitée par les parois vaginales et développée de l’utérus à la vulve 3-5.4 : kystes - canal mésonéphrique (ou canal de Gartner) - kyste parauréthral - kyste d’inclusion 3-5.5 : tumeurs - rhabdomyosarcome : le plus souvent au départ de la cloison vaginale antérieure et parfois prolabé à la vulve - adénocarcinome (syndrome DES) - attention à l’urétérocèle prolabée dans l’urèthre et pouvant donner le change pour une masse à point de départ vaginal. 4. L’UTERUS - Chez le nouveau-né, l’utérus (col utérin) apparaît souvent turgescent (imprégnation hormonale maternelle) - Son épaisseur et sa longueur diminuent ensuite et restent stables jusqu’à la période pré-pubertaire où une poussée de croissance est à nouveau observée - Période pré-pubertaire : forme typique « en goutte ». L’utérus visible en échographie est essentiellement composé du col, le corps étant peu développé. - Période post-pubertaire : forme typique adulte « en poire », suite au développement du corps et du fond utérins. - Données biométriques : (cf. courbes annexées) utérus longueur (cm) épaisseur du corps (cm) épaisseur du col (cm) -------------------------------------------------------------------------------------------------------------------néonatal 2,3 - 4,6 0,8 - 2,1 0,8 - 2,2 prépubère 2 - 3,3 0,5 - 1 postpubère 5 -8 1,6 - 3

- les malformations sont abordées dans un autre chapitre - les tumeurs sont rares

5. LES OVAIRES 5-1. Ils ne sont pas toujours visibles en échographie et théoriquement plus difficiles à voir chez le petit enfant étant donné leur taille réduite. Si les recommandations techniques exposées plus haut sont suivies, le score de visibilité peut atteindre 90 %. La moyenne de la littérature se situe cependant entre 70 et 80 %. 5-2. Leur position classique est para-utérine, mais il est possible de les observer depuis le pôle inférieur des reins jusqu’au ligament large 5-3. Données biométriques (cf. courbes annexées) ovaires longueur (mm) largeur (mm) épaisseur (mm) volume (ml) ----------------------------------------------------------------------------------------------------------------naissance 15 3 2,5 0,7 - 0,9 puberté 24 - 41 15 - 24 8,5 - 19,4 2 - 10

N.B. : mesure du volume de l’ellipsoïde : L x l x épaisseur x 0.5233 5-4. Il est fondamental de se souvenir que dans toutes les tranches d’âge, de la naissance à la puberté, les ovaires montrent fréquemment des « kystes » (follicules) inférieurs à 10 mm et parfois des macro-kystes (≥ 10 mm) sans aucune pathologie sous-jacente. IL est bien montré actuellement qu’il s’agit d’une variante du développement ovarien normal. Il est primordial de ne pas confondre cet aspect avec le syndrome de Stein-Leventhal (maladie des ovaires polykystiques) qui débute pratiquement toujours après la puberté par une triade clinique composée d’aménorrhée ou oligoménorrhée, hirsutisme et obésité. Ce syndrome comporte également des modifications biologiques hormonales que nous ne détaillons pas ici. Dans ce syndrome, chaque ovaire doit montrer plus de 10 kystes de 2 à 8 mm. 5-5. Les kystes de l’ovaire - présence normale de follicules primaires ≤ à 9 mm - les kystes ovariens représentent 70 % des masses pelviennes chez la fille 5-5.1 : kystes folliculaires - inférieurs à 3 cm - visibles à tous les âges pédiatriques - évolution vers la régression spontanée - parfois sécrétion d’oestrogène induisant une puberté précoce - parfois compliqués d’hémorragie ou de torsion 5-5.2 : kystes simples 5-5.3 : kystes para-ovariens (corps de Rosenmüller) 5-5.4 : kystes du corps jaune - rare avant la puberté - au moment de l’ovulation et le plus souvent asymptomatique - si production oestroprogestative : possibilité d’hémorragie

5-5.5 : cas particulier des kystes néonataux (souvent de découverte anténatale) - nature folliculaire ou luthéïnique (induction par gonadotrophine chorionique maternelle) - plus fréquent si : - diabète gravidique - toxémie gravidique - isoimmunisation maternelle - la régression spontanée est souvent observée si le diamètre est inférieur à 5 cm - complications : - hémorragie ou torsion (cloison - niveau liquide/débris) - rupture rare (ascite) - diagnostic différentiel : - hydrocolpos - kyste de l’ouraque - hydronéphrose - duplication intestinale - traitement : - conservateur : surveiller échographiquement l’involution - aspiration sous guidage échographique si trop grand volume et interférence avec le transit intestinal ou urinaire - chirurgie si récurrence après ponction ou complication de torsion 5-6. La torsion d’annexe le diagnostic échographique n’est pas aisé et le diagnostic différentiel doit se poser avec l’abcès appendiculaire, la tumeur ovarienne, la grossesse extra-utérine et le diverticule de Meckel compliqué notamment. L’image échographique est polymorphe dans cette pathologie mais le plus souvent l’ovaire sera augmenté de volume et d’aspect très hétérogène bien qu’on puisse encore y observer de petits follicules. 5-7. Les tumeurs malignes - elles sont rares et représentent 1 à 2 % des tumeurs malignes de l’enfant - tumeurs épithéliales - tumeurs des cellules germinatives : tératome, dysgerminome et gonadoblastome. - métastases de lymphome, leucémie et neuroblastome. 5-8. Anomalies de la taille des ovaires - ovaires atrétiques dans le syndrome de Turner - ovaires hypoplasiques mais parfois normaux dans les mosaïques de Turner - ovaires augmentés de volume dans hypothyroïdie primaire de longue date syndrome de McCune - Albright syndrome de Stein-Leventhal - puberté précoce : - augmentation symétrique du volume ovarien - augmentation réduite du volume utérin - pseudo-puberté précoce : - ovaires prépubères (parfois kystes) - utérus d’aspect adulte 5-9. Enfin, il ne faut pas oublier que la hernie inguinale chez la fille contient très souvent l’ovaire.

BIBLIOGRAPHIE 1. Bridges NA, Cooke AC, Healy MJR et al. Standards for ovarian volume in childhood and puberty. Fertil Steril 1993; 60 (3) : 456-460. 2. Cohen HL, Eisenberg P, Mandel F et al. Ovarian cysts are common in premenarchal girls : a sonographic study of 101 children 2 - 12 years old. AJR 1992; 159 : 89-91. 3. Fleischer AC, Shawker TH. The role of sonography in pediatric gynecology. Clinical Obstet Gynecol 1987; 30 (3) : 735-746. 4. Griffin IJ, Cole TJ, Duncan KA et al. Pelvic ultrasound measurements in normal girls. Acta Paediatr 1995; 84 : 536-543. 5. Griffin IJ, Cole TJ, Duncan KA et al. Pelvic ultrasound findings in different forms of sexual precocity. Acta Paediatr 1995; 84 : 544-549. 6. Haber HP, Mayer EI. Ultrasound evaluation of uterine and ovarian size from birth to puberty. Pediatr Radiol 1994; 24 : 11-13. 7. Ivarsson SA, Nilsson KO, Phersson PH. Ultrasonography of the pelvic organs in prepubertal and postpubertal grils. Arch Dis Child 1983; 58 : 352-354. 8. Lindsay AN, COORHESS ML, Mac Gillivray MH. Multicystic ovaries in primary hypothyroidism. Obstet Gynecol 1983; 61 (4) : 433-437. 9. Porcu E., Venturoli S, Dal Prato L et al. Frequency and treatment of ovarian cysts in adolescence. Arch Gynecol Obstet 1994; 255 : 69-72. 10. Stanhope R, Adams , Jacobs HS et al. Ovarian ultrasound assessment in normal children idiopathic precocious puberty, and during low dose pulsatile gonadotrophin releasing hormone treatment of hypogonadotrophic hypogonadism. Arch Dis Child 1985; 60 : 116-119. 11. Teele RL, Share JC. Ultrasonography of the female pelvis in childhood and adolescence. Radiol Clin North Am 1992; 30 (4) : 743-758. ---

6. Etude morpho-fonctionnelle de l’endomètre au cours du cycle menstruel Y. ARDAENS

7. L’endomètre au cours du cycle menstruel : apport de l’écho-doppler couleur vaginal Y. ARDAENS

8. Pathologie utérine bénigne Y. ARDAENS

9. Magnetic resonance imaging of uterine malignancies. S.Gryspeerdt, L.Van Hoe

STAGING OF UTERINE AND CERVICAL CANCER

Since MR imaging is superior to CT in the T-staging of uterine cancer, the following presents the different stages of cervical and endometrial carcinomas together with their corresponding features on MR images. Carcinoma of the cervix General features. In younger women, the tumor is characteristically exophytic whereas in older women it is often endocervical due to the proximal migration of the squamo-columnar junction with age. On T1 weighted images, cervical cancer appears as a nodular mass enlarging the normal cervical contour. The signal intensity of the lesion is usually identical to that of the normal cervix. In larger tumoral masses however, haemorrhagic necrosis can be identified as areas of high signal intensity on T1 weighted images. On T2 weighted images, the tumor can be distinguished from the remainding normal cervix by its characteristic higher signal intensity. In the case of large cervical tumors, focal areas of very high signal mark areas of necrosis on T2 weighted images. On dynamic MR images, cervical tumor exhibits an increased uptake of GD-DTPA compared to the myometrium. On post-contrast T1 weighted images, cervical carcinoma shows low signal intensity. The tumor has a signal intensity similar to that of the cervical lips, but lower than that of the myometrium.

* Stage I Stage I tumors are those that are confined to the cervix. High-signal-intensity tumor tissue is seen against the dark background of the cervical stroma on T2- weighted sagital or axial images. The depth of cervical stroma infiltration corresponds to the area of increased signal intensity on T2-weighted images. Application of Gd-DTPA makes is possible to differentiate viable tumor from necrotic areas, but it does not improve tumor detection. Recent studies reported accurate assessment of stage I cervical carcinomas on high resolution imaging of the cervix with a transvaginal coil. * Stage II Precise knowledge of tumor size and location affects the therapeutic decision between surgery and radiation therapy. Surgery is usually reserved for patients in whom tumor is confined to the cervix. In patients in whom tumor has spread to the parametrium or beyond (stage II or more) , radiation therapy is the treatment of choice. Clinical staging has limited accuracy : a discrepancy of 34-39% has been reported between clinical and surgical staging. A major possible role for radiological imaging is thus residing in the preoperative evaluation of tumor spread beyond the cervix. MR imaging has been proven to be superior to CT for the evaluation extracervical spread. Tumors extending beyond the uterus with infiltration of the upper and middle third of the vagina are classified as stage IIa.. Direct evidence for invasion of the vaginal wall is suggested if there is a thickening of the vaginal wall and abnormal signal intensity on T2 weighted images. Tumors extending beyond the uterus with infiltration of the parametrium are classified as stage IIb. Direct evidence of endometrial invasion is suggested if there is extension of nodular soft tissue into the parametrium. Using direct evidence as criterium for extracervical tumor spread suffers from low sensitivity, with many tumors showing vaginal or parametrial involvement on histopathologic examination, without the above described direct evidence for extracervical spread on MR or CT images. Indirect evidence for the presence or abscence of extracervical spread is obtained by evaluating the cervical rim. The visualisation of an uninvolved cervical stromal ring exceeding a thickness of 3mm predicts the abscence of extracervical tumor seedings with a very high negative predictive value. If full-thickness stromal invasion is present, there is a relatively high frequency of microscopic parametrial invasion , even if no parametrial abnormality is seen on MR images. Reports in the literature suggests that parametrial evaluation is not or only slightly improved by application of Gd-DTPA.

*StageIII Deep vaginal invasion without tumor extension to the pelvic wall is classified as FIGO stage IIIa disease. T2-weighted axial MR images show the high- intensity tumor to extend into the lower part of the vagina. Involvement of the pelvic wall or hydronephrosis is present in stage IIIb tumors, which are characterized on axial images by disappearance of the fatty layer medial to the muscular pelvic wall or by macroscopic infiltration of pelvic wall structures. * Stage IV. Stage IVa is defined as tumor infiltration of the bladder and/ or rectum. Invasion of the bladder results from anterior extension of tumor along the peritoneal reflection, referred to as the uterine vesical ligament, which connects the bladder and the cervix. Involvement of the rectum with cervical carcinoma can occur through two different routes.Tumor can invade the sacro-uterine ligaments and follow these structures posteriorly to invade the rectum. This method of spread also may result in invasion of the presacral space and the sacrum itself. The second method of rectal invasion is by direct extension of a posteriorly positioned cervical mass. On axial or sagittal T2-weighted images, the high-signal -intensity tumor masses are seen to involve the wall of the bladder or rectum. For the evaluation of advanced stages with infiltration of the bladder, rectum or pelvic wall, Gd-DTPA has been shown to improve the delineation of tumor tissue from soft- tissue structures in the pelvis. Presence of distant metastases is defined as stage IVb disease irrespective of the local tumor stage.

Lymphatic metastasis occur to the periaortic chains in 17% to 29% of cases. Five percent to 16% of stage IB and IIA lesions will be associated with periaortic lymphadenopathy. Peritoneal seeding is not uncommon with locally advanced disease. Adenocarcinomas show a higher fequancy of lymphatic and hematogeneous metastasis.

Carcinoma of the endometrium General features. Ct shows uterine inhomogeneity, with the low-attenuation areas representing tumor. Uterine inhomogeneity is however not a specific CT sign of endometrial carcinoma, and is even not an infallible sign of malignancy. MRI is advantiguous to CT for staging of the endometrial cacinoma. The value of MRI relies in its ability to more accurately assess the local extend of endometrial carcinomas. On T2 weighted images, endometrial carcinoma exhibits a moderately high signal intensity. On dynamic MR images, endometrial carcinoma tumor exhibits a delayed uptake of GD-DTPA compared to the myometrium, thus possibly allowing diagnosis of myometrial invasion. On post-contrast T1 weighted images, endometrial carcinoma is iso- or hypointense to surrounding myometrium.

* Stage Ia. Isointense tumors confined to the endometrium do not always have a clear correlate on MR images. A slight increase in the size of the endometrium or inhomogeneity of its internal structure may be indicative of a stage Ia tumor. On MRI, the endometrial stripe should measure less than 1 cm in premenopausal women, and less than 3 mm in postmenopausal women. Thickening of the endometrial stripe can be the earliest finding of endometrial cancer. Endometrial hyperplasia may however also cause widening of the endometrial canal; MRI can therefore not distinguish endometrial carcinoma from endometrial hyperplasia. The signal intensity may be homogeneously high, similar to that of the normal endometrium, or exhibit a mixtured high and intermediate intensities. Larger lesions can cause marked widening of the endometrial canal and result in enlargement of the entire uterine body. However, the changes depicted by MR imaging are unspecific and may be due to blood cloths or hormone-replacement therapy. Endometrial carcinoma commonly obstructs the internal os, resulting in hematometrocolpos. It may be difficult to distinguish between high signal fluid and high signal tumor within the endometrial canal. Differentiating blood clots from endometrial cancer is improved on GD-DTPA enhanced T1 images. In normal patients, an early enhancement zone of the inner muscle layer can be found. The early enhancement zone of the inner muscle layer should be intact at this tumor stage, though it may sometimes be difficult to delineate the junctional zone in postmenopausal women.

* Stage Ib. This stage is defined by superficial myometrial infiltration ( < 50% of the myometrial wall). Endometrial carcinoma has been found to show a less pronounced uptake of GD-DTPA on dynamic T1 weighted MR images. Disruption of the early enhancement zone of the inner muscle layer on dynamic GD enhanced T1 weighted MR images indicates involvement of the inner layer of the myometrium by the tumor. Disruption of the junctional zone can also be seen on T2 weighted images as an area with increased signal intensity . As already mentioned, a distinct junctional zone , is not always seen in postmenopausal women. A second sign in this case is focal thinning of the myometrium or irregularity of the tumor-myometrial interface. Concentric thinning of the myometrium as well as hematometra are often apparent in larger tumors: these are non-specific findings and do not correlate with myometrial invasion. The accuracy of determination depth of myometrial invasion varies between 82% and 94%. *Stage Ic. Stage Ic is characterized by involvement of the outer muscular layer ( > 50% infiltration) without growth extending beyond the organ. The area of higher signal intensity on T2- weighted images or the relatively lower enhancement of the tumor may extend to the subserous layer. *Stage II. Infiltration of the cervix is defined as stage II endometrial carcinoma, and can easily be depicted on sagittal images. The high-signal-intensity tumor is clearly delineated from the low-signal-intensity normal cervical stroma on T2- weighted sequences. Widening of the cervical canal has been reported as a finding associated with cervical invasion; this finding however , is nonspecific. We found also some difficulties in differentiating polypoid growth into the cervix from cervical invasion, especially in carcinosarcomas (Malignant mixed Mullerian tumors ), since these tumors have tendency to show polypoied growth pattern. Reported accuracy rates for the detection of cervical invasion is 82% to 90%. * Stage III. Extension beyond the serosa of the uterus or adnexal involvement is defined as stage IIIa, growth of the tumor into the vagina as stage IIIb. Visualization of these changes on T2-weighted images is unproblematic in the majority of cases.

*Stage IV. Invasion of adjacent organs (rectum, bladder) by stage IVa tumors is indicated by intramural areas of contrast uptake or increased signal intensity in these organs on T2-

weighted images. Disappearance of the interposed fatty layer is likewise highly suggestive of infiltration. Stage IVb disease is characterized by the presence of distant metastases.

Metastasis to the adnexae or vagina are common in endometrial carcinoma, although frequently microscopic. Pelvic or periaortic lymphatic metastases generally develop before hematogeneous spread to the liver or lung. Positive peritoneal results are far more common than gross peritoneal spread.

10.Embryologie des malformations pelviennes F. RYPENS, S. TROGRLIC, F. AVNI

11.Les dystrophies ovariennes : nouvelle classification anatomo-fonctionnelle Y. ARDAENS, Y. ROBERT, D. DEWAILLY

12.Les ovaires polykystiques : imagerie moderne Y. ARDAENS, D. DEWAILLY, Y. ROBERT

13.Apport de l’échographie et du Doppler couleur dans le dépistage et la surveillance des hyperstimulations ovariennes Y. ARDAENS & al.

14.Ovarian tumors : CT and MRI L. VAN HOE, S. GRYSPEERDT

15.Inflammatoire aandoeningen P.I.D. E. GOES

INFLAMMATOIRE AANDOENINGEN-P.I.D. Dr. E. GOES P.I.D. is infectie van de bovenste vrouwelijke genitale tractus. Ze geeft aanleiding tot een belangrijk aantal sequellen, en is daarom de belangrijkste sexueel overdraagbare bacteriële aandoening. De belangrijkste sequellen zijn infertiliteit, buitenbaarmoederlijke zwangerschap en chronische pijn. Risicofactoren voor het oplopen van P.I.D. zijn multipele sexuele partners, gebruik van een I.U.D., onbehandelde besmette partner, antecedenten van P.I.D., aanwezigheid van Neisseria Gonnorrhoea of Chlamydia in de genitale tractus en frequent vaginaal douchen. P.I.D. geeft vaker aanleiding aan sequellen dan zou mogen omdat de patiënten niet of onvoldoende worden gehospitaliseerd, of omdat ze onvoldoende of verkeerde antibiotica krijgen, of omdat de partner niet behandeld wordt. P.I.D. wordt daarom beschouwd als een van de meest verwaarloosde aandoeningen. Pathogenese Meestal is de infectie ascenderend en polymicrobieel. Soms is de infectie hematogeen (mycoplasma, mycobacteria), of door directe uitbreiding vanuit een ander abdominaal orgaan (diverticulitis, appendicitis). In geval van sexueel overgedragen infecties gaat het meestal om infecties door Neisseria Gonorrhoea of Chlamydia Trachomatis. Neisseria Gonorrhoeae geeft aanleiding tot belangrijkste beschadiging van de tubae, door direct effect van de bacteriën op de gecilieerde epitheliale cellen. Clamydia richt schade aan door middel van een gecompliceerd immunologisch proces. Ze geeft aanleiding tot een auto-immune overgevoeligheid, die na de eliminatie van de Chlamydia verder schade blijft aanrichten. Dit mechanisme geeft aanleiding tot steeds belangrijkere beschadiging als er meer infecties bestaan. Enkel door een vroegtijdige diagnose en behandeling kan men vermijden dat dit mechanisme in werking treedt. Symptomen Men onderscheidt 4 verschillende klinische vormen van P.I.D.: 1) Asymptomatische P.I.D. : de salpinges worden beschadigd zonder dat de patiënte klachten vertoont. De diagnose wordt gesteld bij de oppuntstelling voor infertiliteit. De infectie is meestal door Chlamydia. 2) Atypische P.I.D. : de patienten vertonen erg weinig symptomen, o.m. midcyclisch bloedverlies, spotting, onregelmatige menses, wat vage abdominale last. 3) Acute P.I.D. : de patiënten zijn erg ziek, vertonen belangrijke laag abdominale pijnen, slingerpijn en gezwollen adnexen bij het gynecologisch onderzoek en belangrijk vaginaal en urethraal verlies. 4) Chronisch P.I.D. syndroom : dit komt overeen met de eindfase van de aandoening, met chronische laag abdominale pijn en littekenweefsel t.h.v. de salpinges.

Acute P.I.D. In een vroegtijdig stadium is het transvaginaal echografisch onderzoek volledig normaal. Soms visualiseert men wat vocht t.h.v. het cavum van de baarmoeder. Dit laatste is vaak het enige teken van endometritis. Later ontstaat er hyperaemie, oedeem en tortuositeit van de salpinges. Ze vertonen een purulent exudaat. Dit alles kan alleen maar gevisualiseerd worden als er voldoende vrij vocht bestaat in het kleine bekken om de salpinges af te lijnen.

Hun reflectiviteit is immers dezelfde als deze van de omliggende organen, zodanig dat ze niet zichtbaar zijn indien er onvoldoende vrij vocht is. Het exudaat wordt gewoonlijk in het lumen van het ampullair gedeelte van de salpynx gezien. Het is trouwens dit gedeelte dat het vaakst beschadigd wordt en waar de meeste extra-uteriene zwangerschappen teruggevonden worden. De hyperaemie wordt aangetoond door het doppler onderzoek. De eierstokken zijn globuleus, oedamateus en doorzaaid met kleine kystische structuurtjes, die overeenkomen met geïnfecteerde follikeltjes. Hun wanden zijn moeilijk af te lijnen door het bestaan van een perioophoritis. Er bestaan geen signifante verschillen in RI of PI van de uteriene en ovariele vaten in geval van P.I.D. Tubo-ovarieel abces Het tubo-ovarieel abces is de zwaarste vorm van P.I.D. Het purulent materiaal van de salpinges omringt de ovaria en bereikt de omliggende organen. Er wordt hierdoor een complex adnexieel conglomeraat gevormd, meestal hyporreflectief op echo. De contouren zijn slecht af te lijnen en onregelmatig. Het is vaak moeilijk om in deze structuur de ovaria en de salpinges te individualiseren. Als de aandoening evolueert, wordt de aflijning van het abces steeds onduidelijker,en worden de anatomische structuren steeds moeilijker terug te vinden. Chronisch P.I.D. Cronisch P.I.D. kan ontstaan als gevolg van een acute P.I.D. of volledig asymptomatisch. Obstructie van het distale uiteinde van de salpynx resulteert in een vochtcollectie in het lumen van de salpynx : hydrosalpynx. Echografisch visualiseert men een anechogene tubulaire structuur, absoluut niet gevasculariseerd op doppler. Vaak visualiseert men mucosale plooien en nodulaire projecties in het lumen van de hydrosalpynx. De aanwezigheid van echo’s in het lumen suggereert een pyosalpynx. Het aspect van het ovarium is gewoonlijk normaal, slechts in enkele gevallen is het volume toegenomen. Bij het betasten van de verscheidene organen door de vaginale sonde kan men een verminderde mobiliteit, te wijten aan adhesies, waarnemen. Referenties 1) Expert Committee on Pelvic Inflammatory Disease (1991) Research directions for the 1990’s.Sex Trans Dis 18:46-64 2)Battinger BE, Frair J, Newhall WV, et al : Association of recurrent chlamydial infection with gonorrhea. J Infec Dis, 1989;159:661-669 3)Morrison RP, Manning DS, Caldwell MD : Immunology of chlamydia trachomatis infection : immunoprotective and immunopathogenic responses. Adv Host Defense Mech,1992;8:57-84 4)Patten RM, Vincent LM, Wolner-Hanssen P : Pelvic inflammatory disease : Endovaginal sonography with laparoscopic correlation. J Ultrasound Med,1990;9:681-689

16.L’instabilité du plancher pelvien vue par la C.C.C.N. (Colpo-cysto-défécographie numérisée) M.-H. TANCREDI

17.Colpo-cysto-defecography and MRI in the evaluation of pelvic floor descent in Women D. VANBECKEVOORT & al.

18.Radiologie interventionnelle en Gynéco-Obstétrique D. HENROTEAUX

La radiologie interventionnelle trouve un large domaine d’application en gynécologie. Si les ponctions sont le geste le plus couramment pratiqué, la radiologie interventionnelle offre des alternatives thérapeutiques dans de nombreux domaines : l’hémorragie du post-partum, les varices tuboovariennes ou l’infertilité. Elle peut également jouer un rôle d’adjuvant dans le traitement des néoplasies de la sphère gynécologique. •





Procédures endovasculaires - Embolisation des hémorragies obstétricales. - Adjuvant au traitement des néoplasies pelviennes et de ses complications. - Traitement des varices tubo-ovariennes. Ponctions pelviennes - Ponction-biopsie. - Drainages. Procédures endo-génitales - Recanalisation tubaire. - Traitement des grossesses extra-utérines.

Embolisations des hémorragies obstétricales. Les hémorragies obstétricales restent actuellement une cause de mortalité maternelle importante malgré les progrès en réanimation. En cas d’échecs des traitements classiques restent la ligature des artères iliaques internes ou l’hystérectomie souvent totale. L’embolisation offre une alternatives à ces traitements. Déjà appliquée à de nombreux autres teritoires vasculaires , elle devrait être le traitement de choix des ces hémorragies. Les données de la littérature montrent un taux de succès élevé (97%) avec une très faible proportion d’hystérectomie (10%) en deuxième intention. Ses complications rares (11%) sont le plus souvent mineures et traitées médicalement. Les conséquences d’une éventuelle ischémie du nerf sciatique peuvent être évitée si l’on prend le soin de ne pas emboliser l’artère fessière supérieur. Il semble également que les complications potentielles postembolisations soient plus sévères si la patiente a déjà subi auparavant une ligature de l’artère hypogastrique. Adjuvant au traitement des néoplasies et de ses complications. En cas de tumeurs pelviennes, l’embolisation peut être utile afin de contrôler une hémorragie. Dans ces conditions, les deux artères hypogastrique devraient être embolisées à l’aide de particules de polyvinyl alcool de gros calibre afin de maintenir la perméabilité des plexus capillaires et de prévenir les risques d’une dévascularisation trop importante. La combinaison de la chimio-embolisation à la chirurgie et à la radiothérapie est assez prometteuse dans le traitements des tumeurs pelviennes d’origine gynécologique. Elle permet d’augmenter les concentrations des agents antitumoraux au sein du tiussu néoplasique et de diminuer les effets généraux de ces substances.

Traitement des varices tubo-ovariennes. La congestion pelvienne chronique lié à une congestion veineuse se manifestant par des varicosités pelviennes est une cause fréquente de douleur pelvienne chronique chez la femme. Les traitements médicaux sont peu efficaces à long terme et seule l’hystérectomie radicale semble donner de bon résultat. L’embolisation des veines lombo-ovariennes selon une technique identique au traitement endovasculaire des varicocéles constitue une bonne alternative thérapeutique. Elle permet une une diminution des plaintes chez 75% des patientes et un amendement complet dans presque 60%. La seule complication rapportée est une perforation sans conséquence de la veine ovarienne par le guide (10%). Ponction-Biopsies. C’est le geste de radiologie interventionnelle le plus couramment pratiqué. En pratique, 2 probémes se posent - l’un clinique, à savoir quelles sont les lésions qui peuvent être ponctionnées ? - l’autre technique à savoir quelle quelle voie d’abord (abdominale ou vaginale) et quelle aiguille utiliser? En l’absence de diagnostic antérieur de malignité, les ponctions doivent être limitées aux lésions bégnines c-à-d aux lésions kystiques avec 1 ou 2 fines cloisons sans végétations ou ascite. En présence d’antécédents de néoplasie, la ponction ne sera réalisée que si son résultat influence le traitement. Une lésion kystique maligne peut être ponctionnée à titre palliatif si la néoplasie est à un stade avancé ou en cas de récidive. La voie d’abord dépendra de la localisation de la lésion et de l’expérience du médecin. Suivant le calibre de l’aiguille ( 21G à 17,5G) de ponction, le taux de complication varie de 2% à 4%. Les complications sont rares (4%). Elles peuvent être précoces (3%) essentiellement de type vaguale ou de type douloureux disparaissant en quelques minutes; parfois il s’agit d’hématomes abdominaux ou d’hématurie (0,6%) ne nécessitant habituellement pas de traitement. Les complications à court terme (1%) sont dues à une infection ou à des douleurs abdominales aiguës pouvant nécessiter un geste chirurgical. Drainages. La technique est identique aux drainages abdominaux percutanés. Le même type de cathéter “ queue de cochon” 8F sera utilisé. L’abord pourra être antérieur, transfessier, lateral ou endoluminal (transrectal ou transvaginale) sous contrôle tomodensitométrique ou échographique. Elle peut s’appliquer à toutes les collections liquidiennes post-chirurgicales: urinome, lymphocèle ou abcés. En cas d’inefficacité du traitment médical associant 3 antibiotiques, le drainage des abcés tubo-ovariens constitue une alternative thérapeutique efficace (93%) qui peut permettre d’éviter une chirurgie (dans 83% des cas) souvent mutilante d’un point de vue fonctionnel pour la femme.

Recanalisation tubaire. Dérivé de l’hystéro-salpingographie et des techniques angiographiques, la recanalisation tubaire permet un traitement non chirurgical de la stérilité liée à un obstacle tubaire proximal. La recanalisation à l’aide d’un guide hydrophile 0.035 peut être réalisée en cas d’obstacle proximal chez 68 à 95% des patientes selon les auteurs avec un taux grossesse de 18 à 33%. Le principal inconvient de cette technique est un risque de grossesse extra-utérine de 4.5 à 6%. Mais le risque de grossesse extra-utérine semble surtout lié à la présence simultanée d’ un obstacle distal (adhérences péritubaires, hydrosalpynx,...) que cette technique ne peut pas taiter. La recanalisation donne des résultats comparables à ceux de la chirurgie tubaire proximale mais elle peut être réalisée en ambulatoire et à moindre coût. Elle constitue également une alternative à la fécondation in vitro en cas de stérilité lié à une obstruction tubaire proximale. Traitement des grossesses extra-utérine. Lorsque la grossesse extra-utérine peut être détectée précocement avant rupture ( cf apport de l’US endo-vaginale et des dosages de b-HCG), elle peut traitée par Méthotrexate administré par voie général ce qui peut permettre d’éviter une salpingectomie. Mais ce traitement s’accompagne d’effets secondaires non négligeables. D’après certains auteurs, il est possible d’administrer le Méthotrexate par voie tubaire avec un taux de succès de +/- 75%.

234

II. OBSTETRICS

1. Biométrie, croissance et bienêtre foetaux F. AVNI & al.

Dès le début de son application en obstétrique, l’échographie a été utilisée pour estimer l’âge gestationnel à partir de mesures foetales, celle du diamètre bipariétal essentiellement. Peu à peu, toutes les structures foetales ont été mesurées et les valeurs confrontées à l’âge gestationnel. Ceci a permis dans un deuxième temps d’évaluer la croissance d’un foetus d’un examen à l’autre. Aujourd’hui, on ajoute une troisième dimension plus difficile à objectiver, la potentialité de croissance d’un foetus. A côté des mesures et de l’évaluation anatomique, les échographistes se sont beaucoup attachés à apprécier le bien-être foetal à partir de l’observation de son activité, en temps réel. De plus l’apparition du Doppler a ajouté un élément objectif dans l’étude de la circulation foeto-maternelle.

1. BIOMETRIE ET CROISSANCE FOETALES

Historiquement, le diamètre bipariétal (DBP) a été la première mesure effectuée. La technique de mesure est bien standardisée sur une coupe transverse du crâne passant par les noyaux de la base et le 3ème ventricule. Si l’âge gestationnel est certain, le résultat est exprimé en percentile par rapport à cet âge. Dans les autres cas, l’âge est estimé par rapport au percentile 50 de la mesure, tout en sachant que l’erreur peut être de 8-10 jours. D’autres mesures ont suivi celle du bipariétal et des normogrammes existent pour quasi toutes les structures et organes foetaux. Dans la pratique journalière seule, le DBP, la circonférence abdominale (CA) et la diaphyse fémorale sont mesurés de manière systématique. Les mesures d’autres structures ne sont utilisés qu’en fonction des résultats normaux de l’examen. On peut aussi ajouter des mesures plus particulières : DIO, longueur du pied ou encore diamètre transverse du cervelet car leur valeur permet de complèter de manière objective les mesures classiques (rapport DIO/BIP constant = 0,47; rapport pied/fémur = 1; diamètre du cervelet = âge en semaines avant 24 semaines). Durant le 2ème trimestre, les mesures sont surtout utilisées pour confirmer l’âge gestationnel, durant le troisième trimestre, les mesures sont surtout utilisées pour évaluer la croissance foetale et éventuellement le poids. Des mesures méticuleuses et répétées des foetus durant la grossesse, tendent à démontrer que la croissance foetale

n’est en aucune manière linéaire. La croissance est plus rapide durant le deuxième trimestre puis tend à se ralentir durant le troisième trimestre. Pour certains, cette constatation a entraîné une remise en question de l’efficacité de l’échographie à dépister les problèmes de croissance. Pour ces auteurs, il est plus important de baser les estimations sur les « potentiels de croissance » d’un foetus que sur ses mesures au 3ème trimestre. Pour être complet, il faut rappeler que de 9 à 12 semaines, l’âge gestationnel est évalué par la mesure du CRL (distance tête-fesses) et le pôle céphalique peut aussi être mesuré.

2. TROUBLES DE LA CROISSANCE FOETALE

Un foetus peut avoir une croissance anormale soit par excès soit par défaut. Par excès, on parle alors de macrosomie, les mesures se situent au delà du P95 pour l’âge et le poids foetal dépasse les 4 kg à terme. Ce poids foetal peut s’estimer par différentes formules associant le BIP, la CA et/ou le fémur. Toutes les formules se valent et il faut savoir que les calculs sont grevés d’une erreur de 15 à 18% et donc l’erreur en poids est d’autant plus importante que le poids est élevé. Les bébés macrosomes résultent souvent de grossesses chez des mères diabétiques; ils risquent une morbidité accrue du fait d’accouchements plus difficiles.

A l’inverse, lorsque la croissance est insuffisante, on parle in utéro de retard de croissance et à la naissance de dysmaturité. Cette insuffisance de croissance peut se marquer tôt dans la grossesse ou plus souvent durant le 3ème trimestre. Il semblerait que les cas dépistés précocement présentent un risque plus élevé de malformations et d’anomalies chromosomiques. Le diagnostic d’un retard de croissance se fait par la démonstration d’un ralentissement de la croissance soit global (= retard de croissance symétrique) soit localisé (= retard de croissance asymétrique intéressant la CA et épargnant le Bip) - le 2ème type survient plutôt durant le 3ème trimestre. Ces cas s’accompagnent souvent d’oligoamnios.

Quel que soit le type de retard, une mise au point complète est nécessaire en recherchant des malformations anatomiques, une anomalie chromosomique, les signes d’infection et toute intoxication médicamenteuse ou autre permettent d’expliquer le retard de croissance. La croissance devra être suivie par échographies répétées. La difficulté résulte d’essayer de déterminer le meilleur moment pour induire l’accouchement. L’analyse du sang foetal prélevé au cordon, le doppler et l’évaluation de l’activité foetale sont des éléments pouvant aider à la prise de décision.

3. L’ANALYSE PAR ECHO-DOPPLER DE LA CIRCULATION FOETOMATERNELLE

Le développement des techniques doppler et doppler couleur ont permis d’étudier in vivo la circulation foeto-maternelle normale et pathologique. Trois sites sont particulièrement étudiés : les artères utéroplacentaires, les artères ombilicales et les artères cérébrales foetales. D’autres vaisseaux sont moins systématiquement étudiés (aorte, artères rénales...). Enfin plus récemment, le côté veineux de la circulation foetale a suscité un intérêt croissant dans le cadre de l’évaluation pronostic des retards de croissance. Les résultats s’expriment en terme de rapports plutôt que des données brutes trop aléatoires. Nous utilisons l’indice de résistance (IR = systole diastole/systole); des tableaux des valeurs normales existent pour chaque vaisseau. Très vite s’est posée l’utilité du dépistage précoce par Doppler de grossesses à risques dans une cohorte de grossesses normales. A ce jour aucune étude prospective n’a pu le démontrer. Par contre, cette utilité semble acquise dans le groupe de grossesses à risques (retard de croissance, préeclampie...) afin de détecter des signes d’évolution péjorative. Les anomalies peuvent se traduire par une augmentation de la résistance artérielle utérine ou ombilicale, l’inversion de la composante diastolique au niveau ombilicale, la diminution de la résistance au niveau cérébrale. Ces deux derniers éléments étant les constatations les plus péjoratives. Les foetus présentant ces altérations ont une mortalité et une morbidité accrues.

4. BIEN-ETRE FOETAL

Le bien-être foetal peut s’évaluer tout d’abord au travers de sa bonne croissance, de son développement morphologique et de son environnement (= volume de liquide amniotique). De plus, l’observation en temps réel de l’activité foetale permet d’identifier des stades dans son évolution neuro-végétative. Le passage d’un stade à un autre plus évolué permet d’objectiver un développement normal. On passe de mouvements globaux peu différentiés à 8-9 semaines à des mouvements de baillement ou de succion à 12-13 semaines. Les mouvements occulaires ont également suscités de nombreuses études et de confrontations avec le développement du système nerveux central à partir de 16-17 semaines. Des troubles majeurs de la mobilité foetale s’observe dans des syndrômes d’akinésie foetale dont le plus fréquent est celui de Pena-Shokeir, semblable à l’arthrogrypose, de pronostic réservé. Enfin, durant la fin de la grossesse, plusieurs équipes ont établi « le profil biophysique » foetal. Cette évaluation basée sur l’activité et la réactivité foetale ainsi que sur la quantité de liquide amniotique permet dans certaines grossesses d’évolution anormale de déterminer le meilleur moment pour l’accouchement.

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11. Divon MY, HSU HW. Maternal and fetal blood flow velocity waveforms in IUGR. Clin Obstet Gynecol 1992;35:156-169

12. Bonnin Ph, Ciram-Vigneron N, Hernandez D et al. Physiologie et exploration US des circulations foeto-maternelles. Feuillets Radiol 1990;30:465-472

13. Soresson SE, Fouron JC, Orblik SP et al. References values for doppler velocimetric indices from the fetal and placental ends of the umbilical artery during normal pregnancy. J Clin Ultrasound 1993;21:317-324

14. Hendricks SK, Sorensen TK, Yang KY et al. Doppler umbilical artery waveform indices - Normal values from forteen to 42 weeks. Am J Obstet Gynecol 1989;161:761-765

15. Arbeille Ph, Body G, Saliba E et al. Fetal cerebral circulation assessment by doppler US in normal and pathological pregnancies. Eur J Obstet Gynecol Reprod Biol 1988;29:261-273

16. Davies JA, Gallivan S, Spencer JAD. Randomized controlled trial of doppler US screening of placental perfusion during pregnancies. Lancet 1992;340:1299-1303

17. Mc Donnell M, Serra-Serra V, Gaffney G et al. Neonatal outcome after pregnancy complicated by abnormal velocity waveforms in the umbilical artery. Arch Dis Child 1994;70:F84-F89

18. Forouzans I. Absence of end diastolic flow velocity in the umbilical artery : a review. Obstet Gynecol Surrey 1995;50:219-227 19. Eronen N, Kari A, Pesonen E et al. Value of absent or retrograde end-diastolic flow in fetal aorta and umbilical artery as a predictor of perinatal outcome in pregnancy induced hypertension. Acta Paediatz 1993;82:919-924

20. Hecrer K, Campbell S. Characteristics of fetal venous blood flow under normal circonstances and during fetal disease. Ultrasound obstet Gynecol 1996;7:68-83

21. Nijhuis JG. Neurobehavioural development of the fetal brain In Timor Tritschie. Appleton-Little (Ed) Stamford 1996 pp 347-354

22. Horimoto N, Koyanagi T, Maeda H et al. Can brain impairement be detected by in utero behavioural patterns. Arch Dis child 1993;69:3-8

23. Horimoto N, Hepper PG, Shahidullah S, Koyanagi T. Fetal eye movements. Ultrasound Obstet Gynecol 1993;3:362-69

24. Hammond E, Donnenfeld AE. Fetal akinesia. Obstet Gynecol Survey 1995;50:24049

25. Mc Miller DA, Rabello YA, Paul RH. Modified biophysical profile : antepartum testing in the 1990’s. Am J Obstet Gynecol 1996;174:812-17

2. Premier trimestre normal et pathologie de la grossesse Y. ARDAENS

3. Extra-uteriene zwangerschap E. GOES

EXTRA-UTERIENE ZWANGERSCHAP Dr. E. GOES Inleiding Er wordt tegenwoordig verwacht dat de echografist de diagnose stelt en de ectopische zwangerschap dusdanig karakteriseert dat er een aangepaste behandeling kan ingesteld worden. Dit alles is mogelijk geworden dankzij de diagnostische accuuraatheid van de nieuwe transvaginale sonden met color triplex mogelijkheden gecorreleerd met de nieuwe zwangerschaptesten (radioimmunoassay serum bhcg test). Transvaginale echografie is beter dan suprapubische, gezien ze een hogere resolutie heeft. Een intra-uteriene zwangerschap wordt bv. ongeveer een week vroeger gezien transvaginaal dan suprapubisch. Bovendien laat de palpatie van de abdominale organen door de sonde toe meer klinische (pijnlijk, gefixeerd) zowel als meer anatomische informatie te bekomen (visualisatie van een structuur achter een andere, betere aflijning van een structuur). Echografische tekens Er bestaan zowel negatieve als positieve echografische tekens. 1)Negatieve tekens a)Intra-uteriene zwangerschap: levend embryo vruchtzak met dooierzak double decidual sac sign 2)Vals negatieve tekens Intrauteriene pseudo-gestationele zak 3)Indirecte positeve tekens a)lege uterus b)vrij vocht 4)Directe positieve tekens a)Adnexiële zwangerschap: levend embryo tubaire of adnexiële ring complexe of soliede massa b)Abdominale zwangerschap Negatieve tekens a) Intrauteriene zwangerschap De eerste stap in de oppuntstelling van een extra-uteriene zwangerschap is het aantonen van een intra-uteriene zwangerschap. Het samenbestaan van een extra- en een intra-uteriene zwangerschap is namelijk erg zeldzaam (1 op 30000 zwangerschappen), zodanig dat deze mogelijkheid gewoonlijk verwaarloosd wordt. Met de toename van geassisteerde fertilisatie echter, neemt de kans op een heterotopische zwangerschap wel toe (1 op 4OOO ).

Een normale, intra-uteriene zwangerschap kan op 5 weken laatste menses gezien worden met suprapubische echografie, en op 4 weken laatste menses met transvaginale echografie. De diagnose van intra-uteriene zwangerschap kan evenwel niet louter gesteld worden op de visualisatie van een intra-uteriene vochtzak met deciduale reactie. Een pseudogestationale zak kan er immers net zo uitzien. Men zal dus het onderzoek moeten herhalen totdat men een levend embryo met hartslag waarneemt, of minstens totdat men de dooierzak ziet. Deze laatste moet absoluut gezien worden door suprapubische echografie als de vruchtzak 2 cm diameter meet of transvaginaal als de vruchtzak 0,6 à 0,8 cm meet. Het aantonen van een double decidual sac teken is onvoldoende : sommige pseudo-gestationele vruchtzakken mimeren dit teken. Vals negatieve tekens Intrauteriene pseudo-gestationele vruchtzak Een intra-uteriene vochtcollectie, omringd door een deciduale reactie kan een echte vruchtzak nabootsen, en zelfs een soort van double decidual sac teken mimeren. Pseudogestationele vruchtzakken vertonen evenwel nooit bloeddoorstroming op doppler ter hoogte van de deciduale reactie, in tegenstelling tot echte vruchtzakken. Indirecte positieve tekens Lege uterus, discriminatoire zone Het aantonen van een lege uterus bij een zwangere patiënte is een van de oudste echografische tekens van extra-uteriene zwangerschap.Door de radioimmunoassay hcg test kan men evenwel de zwangerschap reeds ongeveer 2 weken voor de echografie diagnosticeren. In dit vroege stadium riskeert men dus een jonge zwangerschap te verwarren met een extra-uteriene. Daarom werd het concept van de discriminatoire zone ingevoerd : dit is de hcg waarde waarop men zeker de intra-uteriene zwangerschap moet zien, indien ze bestaat. Het niet visualiseren van een intra-uteriene zwangerschap, bij een hcg waarde boven de discriminatoire zone, wijst op een abnormale zwangerschap, ofwel een spontane abortus, ofwel een extra-uteriene. Een lege uterus en een hcg waarde onder het niveau van de discriminatoire zone vergt verdere onderzoeken : herhalen van de hcg test en van de echografie, totdat er een zekerheidsdiagnose kan gesteld worden. Vrij abdominaal vocht Vrij vocht in het kleine bekken is alleen maar van enig diagnostisch belang indien het heel belangrijk is of indien het echogeen is. In aanwezigheid van een complexe adnexiële massa verhoogt de aanwezigheid van vocht de specificiteit van 94 tot 99%. Directe positieve tekens Adexiële zwangerschap: i)levende extra-uteriene zwangerschap

Het aantonen van een levend adnexieel embryo is uiteraard het meeste specifieke teken, maar een niet erg gevoelig teken (23%). ii)tubaire of adnexiële ring Een levende adnexiële zwangerschap zit altijd in een vruchtzak. Deze vruchtzak heeft uiteraard hetzelfde aspect als een intra-uteriene vruchtzak, en wordt tubaire of adnexiële ring genoemd. Zij mag niet verward worden met een al dan niet hemorragisch corpus luteum. Volgende morfologische tekens laten differentiatie toe : -vocht in de ipsilaterale salpynx duidt op ectopische zwangerschap; -de boord van de tubaire ring is reflectiever dan het ovarieel weefsel rondom een corpus luteum; -symmetrische boord weefsel rondom de tubaire ring en een assymetrische boord weefsel rondom het corpus luteum; -druk door de transvaginale sonde kan het onafhankelijk bewegen van de ectopische zwangerschap ten opzichte van het ovarium aantonen; -zachte echo’s in de adnexiële structuur duiden op een corpus luteum. iii)complexe of soliede massa Een complexe of solide adnexiële massa, samen met een lege uterus en een positieve zwangerschapstest, (hcg waarde boven de discriminatoire zone) eventueel met vrij abdominaal vocht, is erg suggestief voor ectopische zwangerschap. Dankzij de hoge resolutie van de transvaginale sonden, kan men nu gemakkelijk differentiëren met gepedunculeerde myomen, ovariële tumoren of inflammatoire processen. Het niet visualiseren van het ipsilaterale ovarium laat vermoeden dat de massa feitelijk ovarieel is, en dus geen extra-uteriene zwangerschap is. iv)abdominale zwangerschap Dit is een moeilijke diagnose, die vaak pas gesteld wordt als de zwangerschap vrij ver gevorderd is. Ze wordt meestal gemist door een gebrek aan vermoeden vanwege de echografist.

Nut van kleuren triplex echografie Het gebruik van kleuren triplex echografie zal de sensitiviteit van het onderzoek in belangrijke mate verbeteren en het onderzoek vergemakkelijken (toename van ongeveer 20% sensitiviteit). Redenen: -een pseudo-gestationele vruchtzak vertoont nooit vascularisatie, in tegenstelling tot werkelijke vruchtzakken -een actief corpus luteum is gevasculariseerd

REFERENTIES

1) Cacciatore B: Can the status of tubal pregnancy be predicted with transvaginal sonography? Radiology 1990;177:481-484. 2) Timor-Tritsch IE, Yeh MN, Peisner DB, et al:The use of transvaginal ultrasonography in the diagnosis of ectopic pregnancy. Am J Obstet Gynecol 1989;161:157-161 3) Nyberg D, Mack L, Jeffrey R, et al : Endovaginal sonographic evaluation of ectopic pregnancy : a prospective study. AJR 1987; 149:1181-1186 4) Bree RL, Marn CS : Transvaginalsonographyin the first trimester : Embryology, anatomy, and hcg correlation. Semin Ultrasound CT MR 1990;12-21 5) Bree RL, Ewards M, Bohm VM, et al : Transvaginal sonography in the evaluation of normal early pregnancy : Correlation with hcg level. AJR 1898 ;153: 75-79 6) Nyberg DA, Mack LA, Harvey D, et al : Value of the yolk sac in evaluating early pregnancies. J Ultrasound Med 1988;7:129-135 7) Emerson DS, Cartier MS, Altieri LA, et al : Diagnostic efficacy of endovaginal color flow Doppler in an ectopic pregnancy screening program. Radiology 1992;183 : 413-420 8)Dillon EH, Feyock AL,Taylor KJ : Pseudogestational sacs : Doppler US differentiation from normal or abnormal intra-uterine pregnancies. Radiology 1990;176:359-364 9) Nyberg DA, Hughes MP, Mack LA, et al : Extrauterine findings of ectopic pregnancy of transvaginal US : Importance of echogenic fluid. Radiology 1991;176:823-826 10) Coleman BG : Transvaginal sonography in extrauterine and intrauterine pregnancy. Semin Roentgenol 1991;26:63-74

er

4. La pathologie du 1 trimestre F. AVNI, F. RYPENS, C. DONNER

L'utilisation plus répandue de l'échographie endovaginale (EV) a amené une amélioration de l'évaluation du 1er trimestre de la grossesse normale ou pathologique. L'échographie EV apporte des éléments objectifs permettant un diagnostic plus précoce et plus précis même si un abord transabdominal reste l'examen de base. Devant les symptômes classiques de douleurs abdominales, pertes vaginales et éventuellement masse annexielle, l'évaluation échographique doit différentier entre une pathologie de la grossesse elle-même de l'utérus entourant de la grossesse des annexes du pelvis

Une grossesse normale se définit par la présence par la présence d'une série d'éléments gestationnels et embryonnaires appropriés pour l'âge de la grossesse. Les différentes structures apparaissent suivant une séquence bien établie (voir exposé du Dr Ardaens). A l'inverse, une grossesse anormale se détermine par l'absence de l'un des éléments normaux du développement. Dans l'évaluation, il faut toujours tenir compte d'une possible fécondation tardive et faire "bénéficier" l'embryon de ce doute.

1. Pathologie de la grossesse

1.1. Menace de fausse-couche (MFC) Dans la MFC, l'examen US démontre des signes d'évolutivité embryonnaire ou foetale, essentiellement des battements cardiaques et des mouvements foetaux. Le rôle de l'échographiste est important pour rassurer les futurs parents très inquiets. Dans de nombreux cas, aucune explication n'est retrouvée. Dans d'autres, on peut retrouver un hématome sous chorionique (HSC) ou un élément suggérant l'élimination d'un jumeau ("jumeau évanescent"). L'incidence de HSC varie de 4 à 40% des grossesses suivant les séries (dans 4% l'HSC est supérieur à 50 ml de sang). Ils correspondent à l'accumulation de sang entre le chorion et la déciduale. L'origine n'en est pas connue. Echographiquement, il existe une collection hyper puis hypoéchogène à l'un des bords du sac gestationnel. Le risque de fausse couche est d'environ 10%. On doit à l'échographie la démonstration du

phénomène du jumeau évanescent. Dans ce cadre, l'échographie met en évidence un éventail d'anomalies : 2 sacs mais un embryon, 2 sacs et deux embryons mais un seul présentant les battements cardiaques, 2 sacs et deux embryons dont un présente un retard de croissance précoce. L'attitude est l'expectative, le pronostic pour l'embryon restant est satisfaisant. Des études ont démontré que cette perte de jumeaux pouvait atteindre 15% des grossesses gémellaires. Enfin, un groupe particulier de femmes enceintes peut présenter des pertes hémorragiques durant le 1er trimestre, c'est celui des patientes ayant bénéficié d'une biopsie de villosité dans le cadre d'analyse génétique. Le rôle de l'échographiste est de rassurer en démontrant la viabilité foetale même si un hématome est présent.

1.2. Grossesse évolutive avec malformation foetale Une anomalie du développement foetal peut se rencontrer soit lors de l'examen de routine du 1er trimestre soit à la suite de symptômes suggérant une MFC. Grâce en particulier à l'écho EV, des diagnostics de malformation peuvent être réalisés durant le 1er trimestre. Il s'agit principalement d'hydrops foetal généralisé d'épaississement localisé des tissus mous du cou (entrant dans le cadre d'anomalies chromosomiques) et de malformations du SNC.

1.3. Grossesse non évolutive Environ 10% des grossesses ne se terminent pas par la naissance d'un enfant vivant. Il existe des critères objectifs permettant d'établir la non-évolutilité d'une grossesse durant le 1er trimestre. Par exemple, l'absence de vésicule ombilicale à l'écho EV alors qu'il existe un sac gestationnel de 10 mm est prédictif de non-évolutilité avec une sensibilité de 67% et une spécificité de 100%. L'absence d'embryon et de battements cardiaques avec un sac de 16 mm de diamètre est prédictif avec une sensibilité et une spécificité de 100%. La présence de battements cardiaques n'est d'ailleurs que partiellement rassurante. Un rythme cardiaque embryonnaire en dessous de 90/' reste grevé d'un taux élevé de FC. En échographie transabdominale, l'absence de battements cardiaques chez un embryon de 7 semaines est un critère fortement péjoratif.

Un sac aux contours irréguliers, une discordance entre la taille du sac et l'embryon, un sac gestationnel "vide" sont d'autres éléments. Seul l'absence de battements cardiaques est un élément formel; devant le moindre doute, un contrôle doit être demandé une semaine plus tard; l'absence de croissance de l'embryon entre les 2 semaines sera un autre élément déterminant.

1.4. Maladies trophoblastiques gestationnelles (MTG) La MTG englobe un large éventail de pathologies : la môle hydatiforme partielle ou complète, la môle invasive et le choriocarcinome. L'hypothèse pathogénique actuellement acceptée est que des villosités choriales d'un oeuf clair, éventuellement concomitant à une grossesse évolutive, proliférent de manière anormale. En cas de môle complète, l'hyperplasie trophoblastique est isolée sans autre élément embryonnaire amniotique ou vitellin; en cas de môle partielle, des éléments placentaires (hydropiques) ou foetaux (= môle embryonnée) peuvent coexister. A l'échographie, il existe un oedème marqué du trophoblaste qui apparaît "vésiculé", (aspect en tempête de neige). A un stade précoce, les vésicules sont peu évidents et il peut être difficile de différencier une môle de matériel de fausse couche. La présence de kystes (lutéiniques) multiples de grande taille (4-8 cm) sur les 2 ovaires permet de réaliser le diagnostic qui est alors confirmé par les taux élevé de HCG. Les môles invasives et les choriocarcinomes représentent des formes malignes de la maladie. Le myomètre est envahi. Cliniquement, malgré un curetage, les symptômes de grossesse peuvent persister de même que les pertes vaginales. A échographie du matériel echogène et hétérogène persiste dans la cavité et dans le myomètre. Une analyse par Doppler couleur peut montrer une hypervascularisation qui diminue après chimiothérapie. Des métastases pulmonaires peuvent survenir.

2. Pathologie de l'utérus

Un ou plusieurs myomes peuvent coexister avec une grossesse. L'évolution en est imprévisible mais avec une tendance plutôt résolutive. Leur présence peut entraîner une surévaluation de l'âge gestationnel.

Ils peuvent en imposer pour une masse annexielle et sont souvent accompagnés par des symptômes douloureux liés à leur localisation, leur taille ou une nécrobiose éventuelle. Une autre pathologie utérine pouvant entraîner des problèmes d'interprétations à l'échographie sont les aspects liés à des malformations utérines. L'aspect de la 2è corne varie en fonction du degré de la réaction déciduale.

3. Pathologie annexielle

Au niveau des annexes, on visualise fréquemment des formations kystiques correspondant à des kystes résiduels du corps jaune. Ils sont habituellement hypoéchogènes et de diamètre inférieur à 5 cm. Ils disparaissent progressivement. Les femmes ayant subi une stimulation hormonale dans le cadre de procréations assistées peuvent en présenter au début de la grossesse. Les séquelles, parfois même sous la forme du syndrome d'hyperstimulation avec tout l'éventail de ses caractéristiques échographiques (ovaires avec kystes multiples parfois hémorragiques, ascite...). Enfin, des masses tumorales annexielles peuvent être découvertes en début de grossesse parfois même à la suite d'une torsion.

4. Pathologie maternelle pelvienne

Devant une symptomatologie douloureuse pelvienne, chez une femme enceinte, il ne faut pas oublier d'envisager les problèmes urinaires (lithiase, infection, rein pelvien) l'appendicite ou l'infection tubo-ovarienne! Dans la majorité des cas, ces diagnostics sont (très) difficiles à confirmer par échographie seule.

En conclusion, échographie pelvienne plus particulièrement endovaginale a un rôle majeur pour différencier les différentes patrologies pouvant survenir durant le 1er tiers de la grossesse. L'échographiste a lui aussi un rôle majeur pour rassurer les futurs parents très anxieux.

REFERENCES

1. Coleman BG. Transvaginal US in extrauterine and intrauterine pregnancy. Semin Roentgenol 1991; 26 : 63-74.

2. Warren WB, Timor-Trisch I, Peisner DB, Raju S and Rosen MG. Dating the early pregnancy by sequential appearance of embryonic structures. Am J Obstet Gynecol 1989; 161 : 747-753.

3. Howe RS. Early pregnancy : normal and abnormal. Clin Obstet Gynecol 1996; 39 : 188-198.

4. Goldstein SR. Sonography in early pregnancy failure. Clin Obstet Gynecol 1994; 37 : 681-692.

5. Pearlstone M and Baxi L. Subchorionic hematoma : a review. Obstet Gynecol Review 1993; 48 : 65-68.

6. Benson CB, Doubilet PM and Laks MP. Outcome of twin gestational following US demonstration of two heart beats in the first trimester. Ultrasound Obstet Gynecol 1993; 3 : 343-345.

7. Frates MC, Benson CB, Doubilet PM. Pregnancy outcome after a first trimester US demonstrating fetal cardiac activity. J Ultrasound Med 1993; 12 : 383-386.

8. Rottem S, Bronshtein M. Transvaginal US diagnosis of congenital anomalies between 9 weeks and 16 weeks, menstrual age. J Clin Ultrasound 1990; 18 : 307-314.

9. Snijders RJM, Johnson S, Sebine NJ, Noble PL, Nicolaides HC. First-trimester US screening for chromosomal defects. Ultrasound Obstet Gynecol 1996; 7 : 216-226.

10. Nishi T, Nakano R. Amniotic band syndrome : serial US observations in the first trimester. J Clin Ultrasound 1994; 22 : 275-278.

11. Falco P, Milano V, Pilu G, David C, Grisolai G, Rizzo N, Boricelli L. US of pregnancies with first-trimester bleeding and a viable embryo : a study of prognostic indicators by logistic regression analysis. Ultrasound Obstet Gynecol 1996; 7 : 165-169.

12. Goldstein DR. Embryonic death in early pregnancy : a new look at the first trimester. Obst Gynecol 1994; 84 : 294-297.

13. Benson CB, Doubilet PM. Slow embryonic heart rate in early first trimester indicator of poor pregnancy outcome. Radiology 1994; 192 : 343-344.

14. Doubilet PM, Benson CB. Embryonic heart rate in the early first trimester : what rate is normal? J Ultrasound Med 1995; 14 : 431-434.

15. Kawano M, Masuzaki H, Ishiman T. Transvaginal color doppler studies in gestational trophoblastic disease. Ultrasound Obstet Gynecol 1996; 7 : 197-200.

16. Achion R, Goldenberg M, Lipitz S, Mashiach S. Transvaginal duplex doppler US in bleeding patients suspected of having residual trophoblastic tissue. Obstet Gynecol 1993; 81 : 507-511.

17. Strobelt N, Ghidini A, Cavallona M, Pensabene I, Ceruti P, Vergani P. Natural history of uterine leiomyoma in pregnancy. J Ultrasound Med 1994; 13 : 399-401.

18. Perrot N, Boudghene F. Echographie endovaginale. 2è Edition, Masson, 1992.

5. Prenatal sonographic diagnosis of fetal gastrointestinal malformations Ph. CLAPUYT, D. CLAUS

The present chapter describes the sonographic approach to the main fetal intraabdominal abnormalities with the exception of the retroperitoneum, genitalia, abdominal wall defects and diaphragmatic hernia.

It includes the following sections:

I Normal embryologic development II Anatomic description III Abdominal obstruction 1. Organic obstruction: gastrointestinal atresias 2. Functional bowel obstruction: (a) Endoluminal obstruction - meconium ileus (b) Non obstructive small bowel dilatation

IV Tumor masses 1. cystic masses 2. solid masses

V Intra-abdominal calcifications 1. peritoneal calcifications 2. intraluminal intestinal calcifications

3. parenchymal calcifications (liver - spleen) 4. vascular and biliary calcifications.

I NORMAL EMBRYOLOGIC DEVELOPMENT

The primitive gut starts forming at the fifth menstrual week and consists of three parts: the foregut, midgut and hindgut. The foregut includes the pharynx, respiratory tract, esophagus, stomach, proximal duodenum, liver, and pancreas. Derivatives of the midgut include the small bowel and proximal large bowel. Derivatives of the hindgut include the distal colon, rectum, and two proximal thirds of the vagina and urinary bladder. From a functional point of view, intestinal peristalsis begins approximately by 11 menstrual weeks and fetal swallowing begins shortly thereafter. From this time on, fluid movements from the amniotic cavity to the fetal digestive tract take place. The stomach fills in and fluid is propelled to the small bowel and colon where it is resorbed; it is excreted by the kidneys. Filling of the bladder progressively develops. Anomalies

in

amniotic

fluid

dynamics

resulting

in

polyhydramnios

or

oligohydramnios must induce the physician to investigating a possible gastrointestinal tract abnormality (3,44).

Polyhydramnios may be due to a major deglutition disorder (e.g. severe neurologic disorder)

or

proximal

gastrointestinal

obstruction

(e.g.

esophageal

atresia).

Oligohydramnios is less common in gastrointestinal disorders, but it may be observed in certain forms of anorectal malformations with colovesical fistula.

II ANATOMIC DESCRIPTION

Sonographic examination must enable observation of the gastrointestinal anatomic structures at any stage of fetal development. At the abdominal level, the vascular structures are essential landmarks. The venous side consists of the umbilical vein, the portal vein and its tributaries, the venous canal of Arantius, and the inferior vena cava. The arterial side consists of the abdominal aorta and its tributaries, and the umbilical arteries, which constitute essential landmarks at the level of the pelvis minor, where they outline the outer bladder wall. The liver, gallbladder, and spleen are invariably visualized. Visualization of the pancreas is more aleatory due to its echostructure very similar to that of the adjacing gut (32). The development of fetal swallowing permits sonographic visualization of the stomach by the 11th menstrual week (11). By 16 weeks, the stomach should be demonstrated in nearly all normal fetuses (25). Throughout the first and second trimester, the small bowel is normally visualized as a central mass of increased echogenicity (20,22,55). It subsequently becomes less echogenic. Observation of a hyperechoic small bowel during the last trimester of pregnancy must arouse suspicion of

fetal distress (42). The pathologic conditions resulting in fetal distress increase protection of the major territories (brain, heart and kidneys) and vasoconstriction in the upper mesenteric territory, resulting in a more or less severe gastrointestinal hypoxia. The intestinal walls become edematous and thickened and the intestine appears markedly hyperechoic. The large bowel progressively enlarges throughout pregnancy due to the filling of its lumen with meconium. It measures 3 to 5 mm in diameter at 20 weeks and may reach 20 mm or occasionally more near term (66). Characteristically, the large bowel appears as a hypoechoic tubular structure located in the periphery of the abdomen. The intra-abdominal topography of the major parenchymes must be identified relatively to the global position of the fetus in order to detect a possible abdominal situs inversus. Abdominal situs inversus may be associated with anomalies including Kartagener's syndrome, asplenia-polysplenia syndrome (16), and bile ducts atresia.

III ABDOMINAL OBSTRUCTION

Obstructive disorders of the gut are usually easy to detect with ultrasound, as the direct consequence of obstruction is in most instances dilatation of the upper intestinal segment. This is true for the proximal and middle portion of the gut. It is less reliable when obstruction develops distally (colon, rectum). In such case, dilatation of the proximal segment is less obvious and occurs later during pregnancy (2,17).

1. Organic obstruction - Gastrointestinal atresias

The common feature to gastrointestinal atresias is complete obstruction on a gastrointestinal segment resulting in impaired transit of the bowel contents. Invariably, there is prolonged stasis in the bowel segment upperly to the point of atresia and consequently dilatation. The most frequent forms of atresia and their sonographic features are as follows:

(a) Esophageal atresia

Esophageal atresia occurs in 1 in 2500 to 4000 live births. Five types are commonly described, and type III is by far the most common, comprising 80 to 90 % of cases (33). The key to diagnosis is not the failure to visualize the fetal stomach, as it is often mistakenly believed. In the most frequent type of esophageal atresia, there is a fistula between the tracheobronchial tree and the esophageal segment proximal to the point of atresia (56). The swallowed and inhaled amniotic fluid passes into the stomach through the trachea, resulting in visualization of the stomach, even when it is of small dimensions. Causes of non-visualization of the stomach in the fetal abdomen include diaphragmatic hernia, central nervous system anomalies, deglutition disorders, oligohydramnios,etc... Nonvisualization of the stomach can however only be ascertained if repeat scanning has been obtained (57).

The sonographic sign pathognomonic for esophageal atresia is visualization of a dilated upper esophageal cul-de-sac during fetal swallowing (Fig.1). This sign should be investigated by close observation of the cervical region. In rare instances, regurgitation may be visualized (11,19). Polyhydramnios secondary to impaired fluid transit beyond the atretic bowel segment is invariably observed. Polyhydramnios usually accompanies the bowel dilatation, particularly when a proximal bowel obstruction is present. Finally, associated malformations are seen in 50 to 70 % of cases and are recognized by the acronym VACTERL (vertebral anomalies, anorectal atresia, cardiovascular malformations, tracheoesophageal fistula, renal anomalies, and limb abnormalities). These entities should also be investigated sonographically.

(b) Duodenal atresia

The site of obstruction typically is at the level of the second duodenum. Sonographic detection of duodenal atresia may be established early in pregnancy, as some cases have been described during the 18th and 20th week of gestation (61). The characteristic ultrasonic finding is the "double bubble" sign representing the fluid-filled stomach and the proximal duodenum (Fig. 2). It is fundamental to visualize the continuity between the two bubbles, as other cystic masses in the area may produce a similar appearance (in particular choledocal cysts and gastric or duodenal duplications) (8,28).

Concurrent skeletal (36 %), gastrointestinal (26 %), and cardiac (20 %) malformations are often associated. Amniocentesis or cordocentesis is fundamental to exclude a chromosomal anomaly (trisomy 21) associated in 30% of duodenal atresias.

(c) Jejunoileal atresia

Jejunoileal atresia may be observed at any level in the small bowel (23,51). Diagnosis is often late, usually not prior to 24 weeks, and depends on visualization of a dilated small bowel segment of varying size, usually in association with polyhydramnios. Sonographic distinction from other infrequent entities such as Hirschsprung's disease or congenital chloridorrhea is seldom possible. Confusion with ureterohydronephrosis or other intra-abdominal cystic masses (ovarian cyst, choledochal cyst, mesenteric cyst etc...) should also be avoided. Associated extraintestinal anomalies are infrequent (less than 7 %).

(d) Colon atresia and anorectal malformations (10,29)

Sonographic diagnosis of colon atresia and anorectal malformations is unreliable, as dilatation of the bowel segment proximally to obstruction may be more or less severe and appear earlier or later during pregnancy.

Colon dilatation may be moderate and remain within the range of normal values that may reach 20 mm at term. However, concurrent abnormalities (such as those of the VACTERL syndrome) should call the attention of the sonographer. We are presenting a personal observation of fetal abnormality investigated sonographically during the third trimester of pregnancy (Fig. 3). Dilatation of the peripheral bowel structures is seen. The contents of the -most probably- colic segment is abnormal and composed of a cluster of calcified pellets filling the bowel lumen. Oligohydramnios is also evidenced. On the basis of this constellation of sonographic findings, the diagnosis of anorectal malformation with colovesical fistula was proposed and confirmed at birth. Prolonged bowel stasis secondary to rectal atresia was responsible for colon dilatation. The cause of the intraluminal calcification is unknown, although some authors believe that it is presumably related to prolonged stasis. Other authors have proposed that alkaline urine from a colovesical fistula may predispose to intraluminal meconium calcification (7). In the context of anorectal malformations, intraluminal meconium calcification constitutes a sign of good predictive value (63).

2. Functional obstruction

(a) Endoluminal obstruction - meconium ileus

Meconium ileus is the major entity to consider, as the newborns who develop meconium ileus almost invariably prove to have cystic fibrosis. Diagnosis is uneasy during routine sonographic examination, though knowledge of a family history of cystic fibrosis justifies a more detailed investigation of the sonographic signs of the disease. Meconium ileus is characterized by impaction of abnormally thick meconium. Abnormal meconium composition results from a decrease in the exocrine pancreas secretions. The thick and sticky meconium has an impaired transit and most often remains impacted above the ileocecal valve. In some instances, inspissated meconium may form a meconium plug and result in colonic obstruction. Signs of an echogenic distal small bowel associated with minor bowel dilatation should therefore always be investigated (5,13). Differential diagnosis includes the normally increased echogenic aspect of the distal small bowel during the first two trimesters of pregnancy, and pathologic conditions such as chromosomal aberration, viral infection (CMV), etc... Presently, when a family history of cystic fibrosis is reported, modern molecular biology enables a very early diagnosis of the disease (10-12th week) by intestinal microvillar enzyme analysis (47,65).

(b) Non-obstructive small bowell dilatation

Rare functional disorders include: Congenital chloridorrhea, which produces a non-obstructive small bowel dilatation (27,53). This is an autosomal recessive disorder characterized by absent or impaired cellular transport of chloride from the distal ileum and the colon. Postnatal clinical features of congenital chloridorrhea include watery diarrhea, dehydratation, and metabolic alkalosis.

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) (6,58,71). MMIHS is another rare cause of functional bowel obstruction. Over 90 % of reported cases are females. The main sonographic signs include an enlarged non-obstructed urinary bladder that fails to empty, resulting in hydronephrosis. Amniotic fluid is normal or slightly increased in amount.

Finally, Hirschsprung's disease is the most common functionnal disorder and is of uneasy diagnosis during the neonatal period (36,69). Prenatal diagnosis is particularly unreliable, as bowel dilatation is often absent at birth and increases with time. No other sonographic finding contributes to the diagnosis except when abnormalities of the nerves plexus are present over the whole colon, including in some instances the terminal ileum. In these cases, the sonographic pattern is more similar to that of meconium ileus in cystic fibrosis.

IV ABDOMINAL TUMOR MASSES

It is not the aim of the present paper to enumerate all possible diagnoses for abdominal masses. Ultrasound frequently fails to establish a specific diagnosis, though the sonographic aspect of the mass and its topographic relationship to the surrounding organs permit a rather accurate approximation to the disorder pathogenesis. Three sonographic patterns are usually described: anechoic (liquid masses), echogenic (solid masses), and mixed echopattern. The sonolucent (hypoechoic) masses are more likely to be detected sonographically.

1. Cystic masses

The abdominal cystic masses include the enteric duplication cysts, mesenteric cysts, choledochal cyst, and liver and spleen cysts (68). Enteric duplication cysts may develop anywhere along the course of the digestive tract (40,44) (Fig. 4). Duplication cysts are located on the mesenteric side of the gut and may communicate with the intestinal lumen gut or not. Sonographically, duplication cysts most often appear as anechoic (liquid) masses, in some instances of sligthly echogenic aspect. In the latter case, diagnosis results uneasy.

Mesenteric cysts show a very similar sonographic aspect (39). A mesenteric cyst may be indistinguishable from an enteric duplication cyst. However, a large multilocular sonolucent mass in the middle portion of the abdomen should suggest the diagnosis. Unusual sites of involvement include the kidneys, liver, and spleen (9).

Choledochal cyst or pseudocystic choledochal dilatation are secondary to an abnormality of the biliopancreatic junction (34,59,67). Affected patients have a long common channel of the biliary and main pancreatic ducts that enables reflux of the pancreatic juice into the biliary tree, causing weakness of the bile duct wall (possibly resulting in malignancy). The diagnosis of choledochal cyst should be suggested when an anechoic mass of rather small dimension in close relationship with the liver hilum is demonstrated, and when it is showed that the biliary ducts lead to the cystic mass (18). The pathogenesis of liver and splenic cysts is unclear (15,41). The condition comprises various entities ranging from the uncomplicated biliary cyst to the excavated tumor. When cysts are observed in the liver and spleen simultaneously, a detailed kidney investigation should be performed to rule out the diagnosis of dominant polycystic kidney disease. Differential diagnosis of abdominal cystic masses includes ovarian cyst, hydrometrocolpos, hydronephrosis, other retroperitoneal cysts, and acute adrenal hematoma. Ovarian cyst is the most frequent liquid mass reported in the female fetus. Its location in the abdominal cavity may vary from one examination to another, as it is

characteristically mobile and may fluctuate in position. Ovarian cysts may be complicated by torsion and demonstrate a characteristic fluid-fluid level.

2. Solid masses Sonographic diagnosis of solid masses is particularly difficult, as differentiation between the echostructure of a solid mass and the surrounding echogenic bowel structures is uneasy. The range of possibilities is wide and includes liver vascular tumors and hepatoblastoma, which is the most common malignant liver tumor in the neonate (12,45,48). The most characteristic abdominal tumor is the sacro-coccygeal teratoma which is most often extra-abdominally located (essentially in the perineum). Teratomas may however be observed endopelvically and develop in the presacral space. Their echostructure is often mixed (solid and liquid), and calcifications may be demonstrated (43,64).

V INTRA-ABDOMINAL CALCIFICATIONS

1. Peritoneal calcifications

Peritoneal calcifications resulting from meconium peritonitis is probably the most common cause of intra-abdominal calcification in the fetus. Meconium peritonitis results from bowel perforation, most frequently at the level of the small bowel (14).

Pathogenesis is varied and includes all functional or organic causes of intestinal obstruction (21). Perforation results in extravasation of meconium and aseptic chemical peritonitis. The sonographic findings are variable and may be observed independently or simultaneously (24): Ascites (54 %) appears as a liquid and most often finely echogenic mass. It represents the inflammatory response of the peritoneal cavity to the intestinal contents.

Calcified meconium pseudocyst (14 %) results from isolated bowel perforations associated with meconium encapsulation and reactional peripheral calcification (46).

Peritoneal calcifications may be disseminated all over the peritoneal cavity, including the scrotal region (70). Bowel dilatation (27 %) should suggest an associated bowel obstruction, possibly explaining the development of a secondary perforation. In this context, polyhydramnios is present in a majority of cases (64 %). In terms of obstetrics, the prenatal diagnosis of meconium peritonitis is essential. If perforation is major and associated with irruption of a large quantity of abdominal fluid, Cesarean section should be considered. As fetal ascites is incompressible, the overdistended abdomen may be a cause of dystocia and traumatic birth, possibly causing parietal muscular tearing, and vascular and parenchymal lesions. Prenatal diagnosis of bowel dilatation enables adequate and rapid management by the surgical team.

2. Intraluminal intestinal calcifications

Intraluminal intestinal calcification is due to the presence of meconium that secondarily calcifies (72). The most frequent cause of intraluminal intestinal calcification is obstruction to the normal transit of meconium. Prolonged intestinal stasis is thought to increase calcification. As previously described for anorectal malformations with associated colovesical fistula, contamination of the bowel contents by fetal urine is another possible etiologic factor (26).

3. Parenchymal calcifications

Detection of liver calcifications in the absence of tumorous neoplastic or vascular process must induce the practician to investigating fetal infection (30,60,62). Calcifications are commonly associated with varicella or the TORCH complex (toxoplasmosis, rubella, cytomegalovirus, or herpes simplex virus). Liver calcifications may be associated with splenic calcifications. Fetal infection may also result in hepatosplenomegaly. Sonographic signs of fetal infection outside the abdomen should be searched for. At the level of the central nervous system, visualization of parenchymal calcifications in association or not with destructive lesions of the cerebral parenchyme should suggest the diagnosis of transplacental viral infection (essentially toxoplasmosis and cytomegalovirus).

Brain imaging may visualize microcephaly, hydrocephaly, and juxtaependymal lesions (irregular ependymal borders, hyperechogenicity of the ependyma and parenchymal cavities). Confirmation may be obtained by amniocentesis (and cordocentesis) for viral investigation and specific serology. Liver calcifications also have been described from ischemic hepatic necrosis (49). A growing number of authors presently suggest that small solitary liver calcification with no identified cause is not infrequenlty observed, and such a finding probably is of no clinical significance. We personally observed a case of large solitary liver calcification at 16 weeks of gestation (Fig. 5). Viral investigations as well as fetal karyotype analysis were normal. Sonographic follow-up of the lesion showed persistance of the lesion and centrifugal splitting with resulting seeding of smaller calcifications. At birth, the child was well and fit. Sonography demonstrated finely scattered liver calcifications with no particular surrounding and no vascular abnormality. At 3 months of age, calcification had practically resolved. 4. Vascular and biliary calcifications

Biliary lithiasis and intravesicular sludge ball, sometimes in the absence of calcification are the main entities to be considered (1)(Fig. 6). The underlying etiology often remains undetermined after birth. Because the gallstones frequently resolve spontaneously during the first weeks of life, a conservative management should be recommended (35,37,38,54).

CONCLUSIONS

A wide variety of intra-abdominal disorders may be detected on prenatal sonography (4,31). An accurate diagnosis of intra-abdominal abnormalities and disorders can be obtained if the practician has a good knowledge of these entities in the neonate or small infant. Liquid collections are of easy diagnosis on the routine sonographic examinations performed during the second trimester of pregnancy. However, many other abnormalities may be detected by a skilled sonographer, particularly if he has special expertise in fetal anomalies detection. Finally, early detection of fetal intra-abdominal disorders enables determination of appropriate complementary examinations (fetal karyotype, viral investigations, ..) for an adequate follow-up of pregnancy (50), and selection of the adequate mode of delivery and appropriate neonatal medical or surgical management.

Fig. 1. Ultrasound study at 33 weeks of gestation for polyhydramnios : the stomach is poorly visualized. Front view of the fetal neck shows accumulation of fluid and distention of the upper esophageal cul-de-sac during deglutition (arrowheads). Arrows show the trachea.

Type III esophageal atresia was suggested and confirmed at brith.

shoulder; H = head.

S =

Fig. 2. Typical "double bubble" sign in duodenal atresia. Transverse oblique scan of the abdomen shows continuity between stomach and duodenal bulb (arrowheads). The pyloric region is well seen (arrow).

Fig. 3. Imperforate anus with recto vesical fistula. 3 a)Severe oligohydramnios at 33 weeks.

Ultrasound shows an enlarged colon

(arrowheads) containing some hyperechoic foci with posterior shadowing thought to be intraluminal calcifications (arrows). The diagnosis proposed is imperforate anus with rectovesical fistula. 3 b)At birth, Xray of the abdomen shows a distended colon containing multiple meconial calcifications (arrowheads). thereafter confirmed.

Imperforate anus with rectovesical fistula was

Fig. 4. Gastric duplication cyst. 4 a)Front view at the level of the diaphragm during the third trimester (32 weeks). Hour-glass shaped cystic mass astride the diaphragm (arrowheads). Note the close relationship to the stomach (arrows). Diagnosis of diaphragmatic hernia was first proposed. 4 b)At birth, a huge mass (arrowheads) is stretching the lower esophagus and esogastric junction. Surgery revealed a gastric duplication cyst.

Fig. 5. Hepatic calcification. Evolution of a large liver calcification at 16 (5a), 35 weeks of gestation (5b) and 3 months after birth (5c) (arrowheads). No change in the surrounding liver parenchyme or hepatic vessels is found.

Karyotype and serological studies were negative.

The

calcification tends to spread and becomes less visible. It is found again at birth but is hardly visible at 3 months.

Fig. 6. Biliary lithiasis. Transverse scan of the fetal abdomen at 32 weeks. The gallbladder is filled with multiple hyperechoic foci with sparse posterior shadowing (arrowheads). The pattern is typical of biliary lithiasis or at least sludge balls.

ACKNOWLEDGMENTS We personnally acknowledge the invaluable assistance of Jocelyne Burion and Martine Milecan in preparing this manuscript and the professional photographs taken by Patrick Schmitz.

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6. Diagnostic échographique des dilatations des voies urinaires F. AVNI, F. RYPENS, C. SCHULMAN

INTRODUCTION

Les uropathies foetales représentent l'un des groupes les plus larges des anomalies détectées durant les échographies obstétricales (1). De plus le nombre des uropathies découvertes à la naissance a augmenté. L'incidence des anomalies des voies urinaires a augmenté au cours des dernières années passant de 0.25% à 0.6% des naissances dans les séries les plus récentes. Ces éléments ont porté de nombreuses modifications. Les données épidémiologiques ont été modifiées; notre connaissance de l'histoire naturelle de certaines uronéphropathies s'est également nettement modifiée. Le diagnostic, la prise en charge et le traitement des patients présentant une uropathie à la naissance ont également évolué grâce au diagnostic anténatal (2-5). Les uropathies foetales peuvent être séparées en deux groupes : les cas détectés avant 20 à 22 semaines et les cas détectés durant le 3è trimestre de la grossesse. Les cas détectés précocement comprennent les foetus présentant des anomalies sévères (par exemple atrésie urétrale, séquence de Prune-Belly, ...). Ces anomalies s'accompagnent d'oligoamnios et d'hypoplasie pulmonaire, les foetus ont un pronostic réservé (6,7). Le second groupe, le plus large, comprend des cas détectés durant des examens de routine durant le 3è trimestre. Les anomalies rencontrées sont variables : obstruction des voies urinaires supérieures ou inférieures, dysplasie rénale, reflux vésico-urétéral, maladie kystique rénale, ... Chez ces foetus, l'anomalie échographique la plus fréquemment rencontrée est une dilatation des voies urinaires (8).

EVALUATION ECHOGRAPHIQUE DE LA DILATATION DES VOIES URINAIRES FOETALES

Le diagnostic échographique d'une dilatation des voies urinaires se base sur la visualisation d'un bassinet rénal dont le diamètre est > 10 mm (diamètre antéropostérieur sur une coupe transverse), sur la visualisation d'un uretère ou sur une vessie anormalement large et ne se vidant pas au cours du temps (8). Dans une série publiée par Brown et coll. (4), la cause la plus fréquente d'une dilatation des voies urinaires mise en évidence à la naissance était une obstruction à la jonction pyélo-urétérale. Les autres causes étaient dans l'ordre de fréquence une dilatation de l'obstruction de la jonction urétéro-vésicale, des dilatations associées aux duplications rénales et des valves de l'urètre postérieur. Les dysplasies rénales multikystiques correspondaient à environ 13% des anomalies décelées. En cas d'obstruction de la jonction pyélo-urétérale, la dilatation est limitée au système pyélocalyceal et le diagnostic est habituellement facile à réaliser. Le diagnostic différentiel de l'obstruction de la jonction pyélo-urétérale inclut la dysplasie rénale multikystique et l'obstruction urétéro-vésicale. Une dysplasie rénale multikystique a dans la plupart des cas un aspect échographique typique (des kystes multiples de taille variable sans parenchyme rénal et sans bassinet visible) (9). Il existe des formes intermédiaires entre dysplasie rénale multikystique et obstruction de la jonction pyélourétérale plus difficile à classifier donc à diagnostiquer. De plus, le suivi anténatal des uropathies malformatives permet de suivre des cas où on objective une évolution évidente d'un rein hydronephrotique à un rein dysplasique. La mise au point postnatale sera indispensable pour établir le diagnostic correct (10,11). Normalement, les uretères foetaux ne sont pas visibles durant un examen échographique; de ce fait le diagnostic d'une obstruction de la jonction urétéro-vésicale pourra se baser sur la visualisation d'un uretère (8,12). Dans ces cas le diagnostic différentiel inclut le méga-uretères et le reflux vésico-urétéral. Cette différentiation est difficile voire impossible in utéro et sera établie après la naissance. L'incidence des anomalies de la jonction urétéro-vésicale est probablement sous-estimée du fait du péristaltisme urétéral qui peut rendre l'urètre invisible et donc non détectable durant l'échographie (13,14).

Il est intéressant de noter que près de 80% des méga-uretères et reflux vésico-urétéral surviennent chez des bébés de sexe masculin (14,15). L'origine de cette constatation est peu précise. Elle pourrait être liée aux différences embryologiques dans le développement de l'urètre masculin et féminin (16). Dans cette hypothèse, la prédominance masculine pourrait être liée à une dilatation anormale de l'urètre postérieur dans le développement embryologique précoce de l'urètre. Cette dilatation mène à un phénomène de pseudovalves et à une obstruction fonctionnelle de la vidange vésicale. Il s'ensuit une dilatation des voies urinaires supérieures. Cette obstruction peut être transitoire; les reflux et méga-uretères de diagnostic anténatal ou après la naissance peuvent alors être considérés comme séquelles de ce phénomène. Quoi qu'il en soit, 30 à 40% des dilatations urétérales disparaîtront spontanément déjà in utéro ou durant les premiers mois de vie (14,17). Ce phénomène non plus n'a pas encore été clarifié. La duplication rénale est un autre type d'uropathie "redécouvert" grâce au diagnostic anténatal qu'il soit associé à une urétérocèle ectopique ou à une insertion ectopique des uretères. Jusqu'à récemment, une urétérocèle ectopique était diagnostiquée soit comme une masse apparaissant au mea chez des petites filles soit durant la mise au point d'infections urinaires ou de malformations (18). Les insertions ectopiques étaient essentiellement suspectées en cas de perte urinaire. Elles étaient rarement détectées en période périnatale (18). Grâce au diagnostic anténatal, de plus en plus de cas sont détectés dans la période néonatale chez des patients asymptomatiques. L'anomalie se présente en nombre égal chez les garçons et chez les filles et de plus en plus de cas d'insertion ectopique sont identifiés en période néonatale. Tout ceci a modifié et modifiera

les

données

épidémiologiques

classiques

(19,20).

Le

diagnostic

échographique d'un système double est basé sur la visualisation du pyélon supérieur dilaté. Dans des cas favorables l'uretère dilaté peut être suivi jusqu'au niveau du pelvis foetal et il pourrait être possible de différencier les uretères ectopiques des urétérocèles (21,22). Une présentation de siège ou une vessie foetale vide peuvent rendre le diagnostic plus difficile. Il faut d'ailleurs souligner que malgré que le diagnostic anténatal est devenu le moyen le plus habituel de détecter les systèmes doubles, un diagnostic précis n'est en général pas réalisé in utéro; c'est essentiellement la dilatation qui est détectée. La mise au point postnatale permettra de déterminer le type exact de

l'anomalie. Ce manque de spécificité de l'échographie obstétricale a peu d'importance clinique du moment qu'une mise au point uro-radiologique est réalisée après la naissance sous couverture antibiotique prophylactique (19,20). Les duplications peuvent être détectées in utéro comme masse kystique de la région rénale. Ces masses correspondent à des urinomes ou collections d'urine extravasée suite à une rupture calycielle. Ces urinomes sont plus classiquement associés avec des valves de l'urètre postérieur ou des obstructions de la jonction pyélo-urétérale. La rupture calycielle et l'urinome dans le cadre de duplication sont liés probablement à une obstruction aiguë. Ils pourraient survenir à la suite du prolapsus uréthral de l'urétérocèle.

Enfin, une vessie de grande taille (23,24) sans variation de volume au cours du temps suggère une obstruction sous-vésicale. Le degré de la dilatation des voies urinaires supérieures ou l'oligoamnios qui s'y associe est variable et dépend du type d'anomalie et des mécanismes de décompression qui ont suivi l'obstruction. Des valves de l'urètre postérieur constituent l'étiologie la plus fréquente chez le foetus de sexe masculin (25). Le pronostic dépendra du degré d'oligoamnios et du développement pulmonaire. Les cas de plus mauvais pronostic présentent un pneumothorax fatal à la naissance (6,26). Le syndrome megavessie-megauretère en rapport avec un reflux vésico-urétéral massif et le syndrome mégavessie-microcolon hypoperistaltisme sont les principaux diagnostics différentiels. Dans ces deux cas le volume de liquide amniotique est suffisant et le développement pulmonaire normal (27,28).

PRONOSTIC

Le pronostic des uropathies foetales dépend de plusieurs facteurs : le temps du diagnostic, le type de l'anomalie, le caractère uni ou bilatéral de l'anomalie, la sévérité de l'obstruction, la dysplasie associée, la présence de malformation non urologique et l'association avec des anomalies chromosomiques. Plusieurs tentatives de classification ont été réalisées pour évaluer la sévérité de la dilatation et le degré de dysplasie (12,26). La dilatation calycielle et l'amincissement cortical rénal sont des signes suggérant un effet délétère de l'obstruction sur la fonction rénale. L'hyperéchogénicité corticale et la présence de macrokystes corticaux suggèrent fortement la présence de dysplasie (7). Il faut toutefois souligner qu'il n'y a pas de corrélation nécessaire entre l'aspect échographique et la fonction rénale postnatale et que le traitement ne peut être basé sur les constatations échographiques seules. Les anomalies des voies urinaires sont associées avec des anomalies cardiaques, vertébrales ou gastro-intestinales; de ce fait l'examen échographique doit être aussi complet que possible pour exclure des malformations associées. Les anomalies chromosomiques surviennent avec une incidence accrue en cas de malformation urinaire bilatérale ou quand il existe une anomalie d'un autre système que les voies urinaires. Dans ces cas une analyse du caryotype devrait être réalisée (29,30).

PRISE EN CHARGE

Malgré que de nombreux travaux expérimentaux et cliniques aient été réalisés, à ce jour peu d'éléments indiquent que des foetus peuvent bénéficier de dérivations vésicoamniotiques ou de décompression des voies urinaires (5,31,32). De plus il n'y a que peu d'indications de naissances prématurées (cas avec dilatation rapidement croissante ?). A la naissance l'état clinique doit déterminer du meilleur moment pour la réalisation de la mise au point radiologique. Dans la plupart des cas il n'y a pas d'urgence et les examens complémentaires peuvent être programmés. L'échographie est le premier examen réalisé de préférence à la fin de la 1ère semaine de vie. Si l'échographie est réalisée plus précocement, la déshydratation physiologique du nouveau-né peut mener à une sous-estimation de la dilatation (23). S'il n'y a pas de dilatation (moins de 5 mm) un examen de contrôle doit être réalisé à l'âge d'un mois pour éviter des examens fauxnégatifs. Si la dilatation est toujours présente à la naissance, au-delà de 10 mm, une mise au point complémentaire est indispensable sous couverture antibiotique. La prise en charge et la mise au point de cas avec dilatation intermédiaire sont toujours sujettes à débats et controverses. Ils doivent en tout cas être suivis par échographie et si la dilatation augmente, des examens complémentaires doivent être réalisés. En cas d'échographie positive, une cystographie rétrograde doit être réalisée et si un reflux vésico-urétéral est retrouvé, l'enfant doit être mis sous antibiothérapie au long cours. Si aucun reflux n'est présent, une urographie intraveineuse à l'âge d'un mois peut être utile pour déterminer le niveau de l'obstruction et le type de l'anomalie, en particulier en cas de duplication. Le traitement chirurgical, endoscopique ou médical sera décidé sur base des données radiologiques, isotopiques et biologiques tout en tenant compte de la potentialité spontanément résolutive de certaines uropathies. Grâce à cette mise au point standardisée, de moins en moins de cas sont opérés et un traitement conservateur est souvent adopté (5,15,18,34,35,36).

En conclusion, le diagnostic anténatal a profondément modifié la mise au point et les habitudes dans le traitement des uronéphropathies avec bénéfice manifeste pour les patients.

REFERENCES

1. Rosendahl H., Kivinen S. Antenatal Detection of Congenital Malformations by routine US. Obstet. Gynecol 73, 947-951, 1989.

2. Rosendahl H. US screening for fetal urinary tract malformations : a prospective study in general population. Europ. J. Obstet.-Gynecol 36, 27-33, 1990.

3. Helin I., Persson P.H. Prenatal diagnosis of urinary tract abnormalities by US. Pediatrics, 78, 879-883, 1986.

4. Brown T., Mandell J., Lebowitz R.L. Neonatal hydronephrosis in the era of sonography. AJR 148, 959-963, 1987.

5. Cobodny A.H. Antenatal diagnosis and management of urinary abnormalities. Ped. Clin. N. Amer. 34, 1365-71, 1987.

6. Perlman R., Levin M. Fetal Pulmonary hypoplasia anuria and oligohydramnios : clinicopathologic observations and review of the literature. Am. J. Obstet. Gynecol. 52, 1119-1123, 1974.

7. Nicolini U., Tannisandorn Y., Vaughan J., Fisk N.H., Nicolaidis P and Rodeck C.H. Further Predictors of renal dysplasia in fetal obstructive uropathy : bladder pressure and biochemistry of "fresh" urine. Prenatal. Diagn. 11, 159-166, 1991.

8. Cohen H.L., Haller J.O. Diagnostic Sonography of fetal genitourinary tract. Urol. Radiol. 9, 88-98, 1987.

9. Sanders R.C., Hartman D.S. The sonographic distinction between neonatal multicystic kidney and hydronephrosis. Radiology 151, 621-624, 1984.

10. Felson B. and Cussen L.J. The hydronephrotic type of unilateral congenital multicystic disease of the kidney. Semin. Roentgen 10, 113-123, 1975.

11. Avni E.F., Rodesch F., Schulman C.C. Fetal uropathies : diagnostic pitfalls and management. J. Urol. 134, 921-925, 1985.

12. Maizels M., Reisman M.E., Flom L.S., Nelson J., Fernbach S., Firlit C.F., Conway J.J. Grading nephroureteral dilatation detected in the first year of life : correlation with obstruction. J. Urol. 148, 609-614, 1992.

13. Wood B.P., Ben-Ami T., Teele R.L., Rabinowitz R. Uretero-vesical obstruction and megaloureter diagnosis by real-time US. Radiology 156, 79-81, 1985.

14. Avni E.F., Pichot E., Schulman C.C. Neonatal primary megaureters. Trends in diagnosis and management. World J. Urol. 10, 90-93, 1992.

15. Steele B.T., Demaria J. A new perspective on the natural history of VUR. Pediatrics 90, 30-32, 1992.

16. Avni E.F., Gallety E. Rypens F., Hall M., Dedeire S., Schulman C.C. A hypothesis for the higer incidence of VUR and primary megaureters in male babies. Pediatr. Radiol. 22, 1-4, 1992.

17. Rickwood A.M.K., Dee L.D., Williams M.P.L. and Anderson P.A.M. Natural history of obstructed and Pseudo Obstructed megaureters detected by prenatal sonography. Br. J. Urol. 70, 322-325, 1992.

18. Privett J.T., Jeans W.D., Roylance J. The incidence and importance of renal duplication. Clin. Radiol. 27, 521-530, 1976.

19. Winters W.D., Lebowitz R.L. Importance of prenatal detection of hydronephrosis of the upperpole. AJR 155, 125-129, 1990.

20. Avni E.F., Dachen R.J.N., Stallenberg B., Collier F., Hall M., Schulman C.C. Renal duplications : the impact of perinatal ultrasound on diagnosis and management. Eur. Urol. 20, 43-48, 1991.

21. Nussbaum A.R., Dorst J.R., Joffs R.D., Gevart J.P., Sanders R.C. Ectopic ureter and ureterocele : their varied sonographic manifestations. Radiology 159, 227-235, 1986.

22. Jeffrey R.B., Laing F.C., Wing V.W. Sonography of fetal duplex system. Radiology 153, 123-125, 1984.

23. Avni E.F., Thova Y., Van Gansbeke G., Matos C., Droullé F., Didier F., Schulman C.C. The development of hypodysplastic kidney Contribution of antenatal ultrasound. Radiology 164, 123-126, 1985.

24. Rittenberg M.H., Hulbert W.C., Snyder H.M., Duckett J.W. Protective factors in posterior urethral valves. J. Urol. 140, 993-996, 1988.

25. Mahonny B.S., Callen P.W., Filly R.A. Fetal urethral obstruction : US evaluation. Radiology 157, 221-224, 1985.

26. Grignon A., Filion R., Filiatrault D., Robitaille P., Homsy Y., Boutin H., Leblond R. Urinary tract dilatation in utero : Classification and Clinical applications. Radiology 160, 645-647, 1986.

27. Mandell J., Lebowitz R.L., Peters C.A., Estroff J.A., Retik A.B. and Benaceraff B.R. Prenatal diagnosis of the megacystis megaureter association. J. Urol. 148, 1487-1489, 1992.

28. Redman J.F., Jimenez J.F;, Golladay E.S., Leibert J.J. Megacystis - Microcolon - Intestinal Hypoperistalsis syndrome, Case report and review of the litterature. J. Urol. 131, 981-993, 1984.

29. Bois E. Congenital Urinary tract Malformations : epidemiologic and genetic aspects. Clin. Genet. 8, 37-47, 1975.

30. Taybi Radiology of Syndromes Metabolic disorders and skelettal dysplasias. Third edition. Year Book Medical Publishers Chicago 1990.

31. Adzick N.S., Flake A.W., Harrison M.R. Recent advances in prenatal diagnosis and treatment. Pediatr. Clin. N. Amer. 32, 1103-1106, 1985.

32. Drugan A., Zador I.E., Bathia R.K., Sacks A.J., Evans M.I. First trimester diagnosis and early in utero treatment of obstructive uropathy. Acta Obtet-Gynecol. Scand. 68, 645-649, 1989.

33. Laing F.C., Burke V.D., Wing V.W., Jeffrey R.B., Hashimoto. Post-partum evaluation of fetal hydronephrosis : optimal timing for follow-up sonography. Radiology 152, 423-424, 1984.

34. Ransley P.G;, Dhillon H.K., Gordon I., Duffy P.G;, Dillon M.J. and Barratt T.M. The Post-natal management of hydronephrosis diagnosed by prenatal US. J. Urol. 144, 584-587, 1990.

35. Caione P., Zaccara A., Capozza N., De Germano M. How prenatal US can affect the treatment of ureteroceles in neonates. Eur. Urol. 16, 195-199, 1989.

36. Arnold A.J., Rickwood A.M.K. Natural History of Pelviureteric obstruction detected by prenatal sonography. Br. J. Urol. 65, 91-96, 1990.

7. Diagnostic des malformations neurologiques foetales F. RYPENS, F. AVNI

INTRODUCTION - INLEIDING .................................................................................... 5 J.P. JORIS

LE RADIOLOGUE ET LA PATHOLOGIE GYNECO-OBSTETRICALE .................... 12 F. AVNI

NORMAL PELVIC ANATOMY .................................................................................. 22 S.GRYSPEERDT, L.VAN HOE I. GYNAECOLOGY ............................................................................................................................................ 30 1. Physiology of ovaries and uterus ................................................................................................................ 32 E. GOES 2. Pathology of the female pelvis: anatomo-pathological review. .................................................................. 38 S.GRYSPEERDT, L.VAN HOE 3. Principles of MRI and application to studies of the female pelvis ............................................................. 70 L. VAN HOE, S GRYSPEERDT 4. Le Doppler couleur endovaginal en pratique gynécologique ..................................................................... 78 Y. ARDAENS 5. Echographie pelvienne chez la fille : de la naissance à la puberté ........................................................... 104 Ph. CLAPUYT 6. Etude morpho-fonctionnelle de l’endomètre au cours du cycle menstruel ............................................... 116 Y. ARDAENS 7. L’endomètre au cours du cycle menstruel : apport de l’écho-doppler couleur vaginal ............................ 122 Y. ARDAENS 8. Pathologie utérine bénigne ....................................................................................................................... 128 Y. ARDAENS 9. Magnetic resonance imaging of uterine malignancies. ............................................................................. 140 S.GRYSPEERDT, L.VAN HOE 10. Embryologie des malformations pelviennes ........................................................................................... 148 F. RYPENS, S. TROGRLIC, F. AVNI 11. Les dystrophies ovariennes : nouvelle classification anatomo-fonctionnelle ......................................... 154 Y. ARDAENS, Y. ROBERT, D. DEWAILLY 12. Les ovaires polykystiques : imagerie moderne ....................................................................................... 164 Y. ARDAENS, D. DEWAILLY, Y. ROBERT 13. Apport de l’échographie et du Doppler couleur dans le dépistage et la surveillance des hyperstimulations ovariennes .................................................................................................................................................... 170 Y. ARDAENS & al. 14. Ovarian tumors : CT and MRI ............................................................................................................... 180 L. VAN HOE, S. GRYSPEERDT 15. Inflammatoire aandoeningen - P.I.D. ..................................................................................................... 196 E. GOES 16. L’instabilité du plancher pelvien vue par la C.C.C.N. (Colpo-cysto-défécographie numérisée) ............ 200 M.-H. TANCREDI 17. Colpo-cysto-defecography and MRI in the evaluation of pelvic floor descent in Women ..................... 222 D. VANBECKEVOORT & al. 18. Radiologie interventionnelle en Gynéco-Obstétrique............................................................................. 228 II. OBSTETRICS ............................................................................................................................................... 236 1. Biométrie, croissance et bien-être foetaux ............................................................................................... 238 F. AVNI & al. 2. Premier trimestre normal et pathologie de la grossesse ............................................................................ 248 Y. ARDAENS 3. Extra-uteriene zwangerschap.................................................................................................................... 264 E. GOES 4. La pathologie du 1er trimestre................................................................................................................... 270 F. AVNI, F. RYPENS, C. DONNER 5. Prenatal sonographic diagnosis of fetal gastrointestinal malformations ....................................................... 1 Ph. CLAPUYT, D. CLAUS 6. Diagnostic échographique des dilatations des voies urinaires .................................................................... 40 F. AVNI, F. RYPENS, C. SCHULMAN 7. Diagnostic des malformations neurologiques foetales ............................................................................... 55 F. RYPENS, F. AVNI

I wish to express my gratitude to those who have been involved with the production of this textbook, in particular Miss Fabiola Warnon who was very helpful in the preparation of this residential week and the gathering of these texts. I also wish to thank the fellow radiologists who accepted to share their skill and knowledge in the field of gynaecological and obstetrical Imaging. I cannot but feel a deep sense of gratitude to the time they all spent in the preparation of their respective chapters. Finally I wish to thank the Royal Belgian Radiological Society and especially Prof. Dr. A. Baert who first had the idea of the organization by the RBRS of residential weeks for radiologists. I am indebted to him for his financial support as a treasurer of the Society and for his cheerful encouragement. Bouge, october 1996 Jean-Paul A. JORIS.

Verantwoordelijk Uitgever : Editeur Responsable : J.P. JORIS 5310 EGHEZEE

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