Adamsbaum C, Robain O, Cohen P A, Delalande O, Fohlen M, Kalifa G
Service de Radiologie, Hôpital St Vincent de Paul, 82 avenue Denfert Rochereau, F-75 674 Paris Cedex 14, France.
Pediatr Radiol. 1998 Aug;28(8):583-90. doi: 10.1007/s002470050421.
The classification of cerebral cortical dysplasia is difficult and there are histological similarities between focal cortical dysplasia (FCD) and hemimegalencephaly. Objectives. To correlate the MR features and histological data of cortical dysplasias.
The MR appearances of 17 brains were examined. According to the signal intensity within the pathological area on T2-weighted (T2-W) sequences we selected two groups.
Group 1 comprised ten patients with high signal in the dysplastic area on T2-W images. This group included five hemimegalencephalies, three frontal quadramegalencephalies, and one gyral dysplasia. The pathological hemisphere was reduced in size in one case. The cortex was thickened in all cases on T1-weighted (T1-W) images. There was loss of delineation between white matter (WM) and grey matter (GM) in all cases on both T1-W and T2-W sequences. The differential diagnosis with tumour, neoplastic-like malformation or polymicrogyria was questionable. Group 2 comprised seven patients presenting without increased signal within the dysplastic area on T2-W images. WM and GM were of similar signal intensity in six cases, and delineation between white and grey matter was absent in all cases. There were mild abnormalities on T1-W sequences in all cases. The dysplasias were limited to a lobe in five cases and a gyrus in two cases. In all cases, depiction of the malformation was a greater diagnostic problem than the differential diagnosis.
A constant MR sign in our series was the loss of delineation between WM and GM in the dysplastic area. This correlated well with the observed histological disorganisation. Markedly high signal within the dysplastic area seems to be related to myelin abnormalities rather than glial cell abnormalities.
大脑皮质发育异常的分类具有挑战性，局灶性皮质发育异常（FCD）与半侧巨脑症之间存在组织学相似性。目的：将皮质发育异常的磁共振成像（MR）特征与组织学数据相关联。
对17例大脑的MR表现进行检查。根据T2加权（T2-W）序列上病变区域的信号强度，我们选取了两组。
第1组包括10例患者，其T2-W图像上病变区域呈高信号。该组包括5例半侧巨脑症、3例额叶四核巨脑症和1例脑回发育异常。1例患者的病变半球体积减小。所有病例在T1加权（T1-W）图像上皮质均增厚。在T1-W和T2-W序列上，所有病例的白质（WM）和灰质（GM）之间均失去分界。与肿瘤、肿瘤样畸形或多小脑回畸形的鉴别诊断存在疑问。第2组包括7例患者，其T2-W图像上病变区域信号未增高。6例患者的WM和GM信号强度相似，所有病例的白质和灰质之间均无分界。所有病例在T1-W序列上均有轻度异常。5例患者的发育异常局限于一个脑叶，2例局限于一个脑回。在所有病例中，畸形的显示比鉴别诊断更是一个诊断难题。
在我们的系列研究中，一个恒定的MR征象是病变区域WM和GM之间失去分界。这与观察到的组织学紊乱密切相关。病变区域明显的高信号似乎与髓鞘异常而非胶质细胞异常有关。
