Introduction 2D Transient Elastography (TE)

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measurement in placenta: ex vivo comparison between normal pregnancies and placental insufficiencies ... (IUGR) are related to placental insufficiency and.
2D Transient elastography system adapted to Shear Wave Speed dispersion measurement in placenta: ex vivo comparison between normal pregnancies and placental insufficiencies 1,2 1 1 1,3 1,2 4 E. Simon , J.P. Remenieras , G.Marcheteau , F. Patat , F.Perrotin , S.Callé 1 UMR

Inserm U930, University of Tours, France 2 Department of obstetrics, gynecology and fetal medicine, University Hospital Center of Tours, France 3 CIC-IT 806, University Hospital Center of Tours, France 4 GREMAN, UMR CNRS 7347, University of Tours, France Data processing

Preeclampsia and IntraUterine Growth Restriction (IUGR) are related to placental insufficiency and constitute a major public health challenge. Significant changes in placental microarchitecture have already been described in these situations, including, for example, increases or decreases in the number of villi ramifications and presence of fibrin deposits in term villi. These changes affect the entire placenta and might lead to variations in elasticity compared to normal placentas.

Experimental Results Velocity estimator: extension of the autocorrelation estimated by Hoeks et al. Hoeks et al. UMB 20(9),pp.953-965,

1994

Particle velocity Vz(z,t)

Tissue Doppler

In the Fourier domain : plane wave approximation of the axial component of the shear wave Real part of Vz(z,ω):

Ex vivo measurements placentas: [20Hz – 80Hz]

in

2D Transient Elastography (TE)

- 2 vibrating rods placed on either sides of the US probe

PE (n=3)

Cs (m/s) mean ± SD

1.78 ± 0,5

1.04 ± 0.05 1.19 ± 0.16

exponent n mean+/-SD

1.27 ± 0.11

0.99 ± 0.23 1.24 ± 0.27

Shear Wave Speed according to the exponent n healthy IUGR severe IUGR preeclampsia

Animal study (Model of IUGR)

G*(iω)=Ge

n +K.[iω]

Nicolle S. et al., J. Biomechanics 43, pp927-932, 2010

Experimental protocol

- 20 normal, 7 IUGR and 3 preeclampsia placentas (