Volume and shape analysis of the human fetal cerebellum during the early second trimester

The cerebellum,resided in the posterior cranialfossa,is a critical structure.The development of the cerebellum spans a long period and undergoes a dramatic change in its morphological structure.The protracted cerebellar development makes it particularly vulnerable to a wide range of pathologic injuries,especially during the early fetal period.This study characterizes the growth of human fetal cerebellum during the early second trimester.Using 7.0T high-resolution MR images,we manually segmented the fetal cerebellum of 35 specimens with gestational ages ranging from 15 to 22 weeks.V olume measurements and shape analysis were performed to quantitatively evaluate the global and regional cerebellar growth.