Sener R Nuri
Department of Radiology, Ege University Hospital, Bornova, Izmir, Turkey.
AJNR Am J Neuroradiol. 2002 Sep;23(8):1424-6.
Herein the case of a 10-month-old boy with metachromatic leukodystrophy is reported. Diffusion MR imaging performed with an echo-planar trace sequence revealed a cytotoxic edema-like pattern (high signal intensity on b = 1000 s/mm(2) images and low apparent diffusion coefficient values) in the affected white matter in the absence of an ischemic condition. This finding was unchanged at a 6-month follow-up, as revealed by diffusion MR imaging. A gradient-echo diffusion sequence, reverse fast imaging in steady-state precession, revealed hyperintense changes at the corresponding regions. It is likely that the cytotoxic edematous pattern (restricted diffusion pattern) reflected restriction of mobility of the water molecules within abnormal portions of the myelin sheath, because impaired myelin breakdown and reutilization are known features of metachromatic leukodystrophy.
本文报道了一例10个月大患有异染性脑白质营养不良的男孩。采用回波平面追踪序列进行的扩散磁共振成像显示，在无缺血情况时，受累白质出现细胞毒性水肿样模式（在b = 1000 s/mm(2)图像上呈高信号强度，表观扩散系数值低）。扩散磁共振成像显示，6个月随访时这一发现无变化。梯度回波扩散序列，即稳态进动快速成像反转，显示相应区域有高信号改变。细胞毒性水肿模式（扩散受限模式）很可能反映了髓鞘异常部分内水分子移动性的受限，因为髓鞘分解和再利用受损是异染性脑白质营养不良的已知特征。
