Abstract:

Objective　To measure the volume and main dimensions of fetal cerebellum with MRI, and obtain the ranges of their normal values.  Methods　87 fetal specimens without CNS diseases aged from 14-40 gestational weeks were scanned under 3.0T MRI. The cerebellar transverse diameter (TCD), anteroposterior diameter (A-PD), vermis length and cerebellar volume were then calculated by Amira software. Lastly the relationship between these values with fetal age(FA) was analyzed statistically.   Results　The TCD, A-PD and vermis length increased linearitily following the growth of the fetuses [TCD=0.165FA－1.410; A-PD=0.091FA－0.717; vermis length=0.108FA－0.832]. The relationship between cerebellar volume (in cubic centimeters) and FA (in weeks) was well described by a single exponential function [CV=0.034 exp (FA/5.918)]. The doubling time of CV was about 4.1 weeks.   Conclusions　The development of fetal cerebellum could be displayed and quantified by 3.0T MRI, which is valuable for clinical diagnosis and evaluation of fetal development in vivo.

Key words: Foetus, Cerebellum, MR, Specimen