Wang Z, Chen J, Qin Z, Zhang J
Department of Medical Imaging, Nanjing General Hospital of PLA, China.
Chin Med J (Engl). 1998 Jan;111(1):71-4.
To investigate the growth and development of myelin of sheath fetal brain.
Forty-four cases of pregnant women were imaged with magnetic resonance (MR) at 0.35 T (tesla). The signal changes of the main structures of fetal brain were analysed.
The signal intensity of cerebral (except basal ganglia) and cerebellar matter was hypo-signal on the T1WI (T1 weighted spin-echo image), iso-signal of the PDWI (Proton density weighted image) and hyper-signal on the T2WI (T2 weighted spin-echo image). As to the brain stem and basal ganglia, their signal intensities showed difference in different gestational weeks on T1WI. The intensities were of slight hypo-signal before and iso-signal after the 29th week. However, their signal intensities on PDWI and T2WI were the same as those of the cerebral and cerebellar matter.
There was no myelinization of fetal cerebral (except basal ganglia) and cerebellar matter during pregnant period. The myelin sheath was formed in the brain stem and basal ganglia after 29 gestational weeks. The process of myelinization began from brain stem to basal ganglia.
研究胎儿脑白质髓鞘的生长发育情况。
对44例孕妇行0.35T（特斯拉）磁共振（MR）成像，分析胎儿脑主要结构的信号变化。
脑实质（基底节除外）和小脑在T1加权自旋回波图像（T1WI）上呈低信号，在质子密度加权图像（PDWI）上呈等信号，在T2加权自旋回波图像（T2WI）上呈高信号。脑干和基底节在T1WI上不同孕周信号强度有差异，29周前呈轻度低信号，29周后呈等信号。但其在PDWI和T2WI上的信号强度与脑实质和小脑相同。
孕期胎儿脑实质（基底节除外）和小脑无髓鞘形成，29孕周后脑干和基底节开始形成髓鞘，髓鞘化过程从脑干向基底节发展。
