MR Imaging Diagnosis of Central

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Oct 26, 1993 - a lesion in tuber ci- nereum,. Isointense with gray matter, consistent with a hypothalamic ... hamartoma being the most ... in the tuber cinereum,.
1167

MR

Imaging

Diagnosis

Precocious Changes Pituitary

Sharafuddin1 A. Luisiri1 L. R. Garibaldi2 D. L. FuIk’1 J. B. Klein1 K. N. Gillespie3 E. R. Graviss1

M. J. A.

Puberty:

in the Shape Gland

OBJECTIVE. Central precocious stimulation and increased secretion

analyze cious

derived

MR imaging puberty

findings

compared

variables

clinical

matched

variables

with

glands

control

useful in the diagnosis

late MR imaging-derived

Importance of and Size of the

puberty occurs as a result of premature pituitary of gonadotropins. The aims of this study were to

in the pituitary

with

of Central

of children

subjects,

of central precocious the hormonal

profile

with central

to define

puberty, and other

MR

preco-

imaging-

and to cornsimaging

and

findings.

MATERIALS

AND METHODS.

Twenty-six

children

with central

precocious

puberty

(two boys and 24 girls) were divided into two subgroups according to MR imaging findings: idiopathic (21 patients) and nonidiopathic (five patients: three hypothalamic

hamartomas,

one pineal

tumor,

one empty

seila syndrome).

The control

group

con-

sisted of 17 normal age- and sex-matched children (two boys, 1 5 girls). Analyzed parameters included pituitary height, length, width, midsagittal cross-sectional area, calculated volume, and shape. The shape was assessed by a pituitary grading system and two other shape indexes (length-to-height and length-to-width ratios). Pituitary grade was defined by the concavity of the upper pituitary surface (grade 1 = marked concavity, grade 2 = mild concavity, grade 3 = fiat, grade 4 = mild convexity, grade 5 = marked convexity).

RESULTS. Pituitary grade showed a highly significant difference among groups (p .001). Area, height, and length-to-height ratio were significantly different (p < .05), whereas length, width, length-to-width ratio, and volume were not. There was no sig
1 SD below average), nor‘

mal, or elevated (>1 SD above average), adjusted normative values [22]. Peak LH

classified

as normal, early pubertal,

as compared with ageand peak estradiol’ were

or advanced

pubertal.

Multiple-regression analysis of selected MR imaging-derived variables was performed by using forced variable entry and forward stepwise variable entry methods to determine the combination most useful in correctly classifying patients into CPP and healthy groups. Variables analyzed were pituitary grade, area, height, length, width, length/height, length/width, and volume. The significance of height on area being greater than 1 SD from the corresponding mean in the control group (heights and areaa, respectively) was also studied. Finally, in the CPP group, we performed two-tailed significance ttesting

on height,

or normal)

and

area,

results

and

pituitary

grade

of pelvic

enlargement on not), respectively. also performed among selected height, length, width, insulin-like

by bone

age

sonography

Grad.

Fig. 4.-Distribution of pituitary grade by group. Grade 1 = crescent shape, grade 2 = mild concavity, grade 3 = flat, grade 4 = mild convexity, grade 5 = spherical, ICPP = Idiopathic central precocious puberty, NICPP = nonidlopathic central precocious puberty.

of the anterior pituitary relative to the pons in any of the patients. Visualization of the posterior pituitary by group was not significantly different. Differences between NICPP and control subjects were less significant, pnobably reflecting the small number of subjects in this subgroup (Table 1). Comparisons between the ICPP and NICPP subgroups showed no significant difference in any of the variables studed, namely, age, sex, Tanner stage, pelvic sonognams, bone age, insulin-like growth factor I, insulin-like growth factor I’, peak LH, peak LH’, peak estradiol, peak estradiol’, pituitary grade, height, length, width, length/height, length/width, and volume (Tables 1 and 2). in addition, when selected vanables (pituitary grade, area, height, length) in the CPP group were stratified by bone age and pelvic sonognaphic findings, patients with advanced bone age had a significantly higher pituitary grade (p < .01) and had a tendency toward greater length (p < .09), but no significant difference in height on area. Gonadal or uterine enlargement on sonography had no significant effect on the same variables. Cross-correlation analysis of pituitary gnade, area, length, height, width, insulin-like growth factor I’, peak LH’, and

(advanced

(utenine/gonadal

Cross-correlation analysis was variables (pituitary grade, area, growth factor I, peak LH, peak

estradiol).

Results Age and sex showed no significant difference among the studied groups, with the exception of age between control and NICPP groups (p < .05) (Table 1 ). This probably reflects the younger age of onset of symptoms in children with hypothalamic hamartoma [6]. Comparison of the three groups by analysis of variance yielded three parametric variables that differed significantly between ICPP and control subjects: area, height, and length/height (p < .05), whereas length, width, length/width, and volume were not significantly different. Pituitary grade showed a highly significant difference among groups (p < .001) (Fig. 4). There was no visual difference in the intensity

TABLE

1 : Ages and MR Imaging

Height

Length

(n

=

17)

1-10

(n

=

3.52

(n

=

17)

4.89

± 0.26

(n

=

(mm)

7.86 ± 0.43 (n

± 0.36

8.16

Area

(mm2)

Length/height

Length/width Volume (mm3) Note.-All =

± 0.30

=

1 7)

8.22

(n

=

± 0.82

(n

=

15)

7.60 ± 0.46 (n

=

24.6 ± 2.1

(n

=

17)

33.8

(n

=

2.61

(n

=

1 7)

1 .75 ± 0.1 1 (n

=

=

15)

1.12

± 0.07

(n

=

=

1 5)

1 54.8

± 1 4.8

(n

=

± 0.35

1.07 ± 0.12 (n 1 26.2 ± 1 8.4 (n

values except age are expressed

not significant.

[7]

as mean

±

SE. ICPP

=

± 2.7

idiopathic

Groups

NICPP

ICPP

3-10 [8]

(mm)

(yr)

Gland in ICPP, NICPP, and Control

(mm)

Width

NS

of the Pituitary

Control

Variable

Age range [median]

Characteristics

21) 21) 21) 20) 19) 21 ) 20) 20)

central

Significance

2-8 [5] 5.15 ± 1 .07 7.23 ± 0.88 9.34 ± 2.34 29.0 ± 7.9 1 .94 ± 0.83 0.95 ± 0.22 184.3 ± 61 .9

precocious

puberty,

(n

=

(n

=

(n

=

(n

=

(n

=

(n

=

(n

=

(n

=

NICPP

5) 5) 5) 5) 5) 5) 5) 5) =

Control Control NS NS Control Control NS NS nonidiopathic

(p

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