关键词: 胎儿, 小脑, MR, 标本 

Abstract:

Objective　To observe the development of human fetal cerebellum with MRI in the second and third trimester.　Methods　87 fetuses that had no morphological brain disorder at 14~40 weeks of gestation were scaned using 3.0T MRI. Transverse, sagittal and coronal images were used to analyze the development of cerebellar structures.　Results　From images, we found that the dentate nucleus was visible at week 16 of gestation. From week 17, the tegmento-vermian angle was invisible. The prepyramidal fissure and the fourth ventricle could be recognized at week 22, whereas the primary fissure was visible at week 20. The second fissure and posterolateral fissure were recognized at week 24. In second and third trimester, the shape and the fissures of cerebellum came into being and the CV also grew rapidly; the ratio of the anterior lobe to the posterior lobe decreased with GA.　Conclusions　The development of the fetal cerebellum in the second and third trimester could be displayed by 3.0T MRI. This study could provide anatomical and imaging data concerning the development of the fetal cerebellum, which is valuable for clinical diagnosis and evaluation of fetal development in vivo.

Key words: Fetal, Cerebellum, MR, Specimen