Methodology And Clinical Value Of Three-dimensional Ultrasound Volume Contrast Imaging In The Measurement Of Fetal Corpus Callosum-tentorium Angle

Objective To establish the ranges of normal reference values of fetal corpus callosum-tentorium angle in normal fetuses at different gestational weeks,and to evaluate their clinical values in the diagnosis of mega cisterna magna and Dandy-Walker malformation.Methods Totally 406 normal singleton fetuses between 19 and 36 weeks of gestation were enrolled.Three-dimensional ultrasound(3D-US)volume contrast imaging-C(VCI-C)was used to measure their CTA,the correlation of CTA with gestational age were investigated respectively.The CTA of 30 fetuses with mega cisterna magna and 11 fetuses with Dandy-Walker malformation were also measured and were compared with those of the normal fetuses.Forty frtuses collected randomly was examined by the same/two different physician to analyzed the repeatability/consistency reliability.Results In these normal fetuses,the CTA showed no correlations with gestational age(r = 0.018,P >0.05).The CTA of 30 fetuses with mega cisterna magna were not significantly different from those of normal fetuses(55.93±3.98° vs 55.01±5.02°,P > 0.05),while the CTA of 11 fetuses with Dandy-Walker malformation were significantly smaller than those of normal fetuses and the fetuses with mega cisterna(32.43±3.11° vs 55.01±5.02°,P<0.05;32.43±3.11° vs 55.93±3.98°,P<0.05).The repeatability of the same physician and the consistency between two different physicians were good,their intraclass correlation coefficient and 95% confidential interval were 0.96(0.92-0.98)and 0.89(0.81-0.95)respectively.Conclusions 3D-US VCI-C is feasible for measuring the CTA of fetuses and the measured values can be used as the reference standards.The measuring of the CTA can help differentiate mega cisterna magna from Dandy-Walker malformation.