局限性脑皮层发育不良的影像与病理对比分析

Correlation analysis of findings from neuroimaging and histopathoiogy in focal cortical dysplasia

目的探讨局限性脑皮层发育不良（FCD）的影像改变，并与病理改变对比，以提高对FCD的认识。方法回顾性分析28例经临床病理证实的FCD患者的临床及影像资料，所有患者均行MR检查，其中14例患者行PET检查，将影像改变与病理变化进行对比分析。结果28例FCD中MRI显示病灶24例（85．7％），4例未显示明显异常，局限性脑皮层增厚及灰、白质界限不清是FCD的主要MR改变，同时脑皮层及皮层下白质可出现多种异常信号，其中皮层下白质内类三角形稍长T2信号指向侧脑室具有一定的特征性。14例行PET检查，其中9例（64．3％）显示病灶局部葡萄糖代谢活性减低。病理改变主要包括脑皮层细胞排列结构紊乱，皮层及皮层下白质内异形神经元细胞及气泡状细胞，部分患者可见皮层下白质髓鞘形成障碍及海绵样坏死灶。结论高质量的MR图像可以显示大部分FCD病灶，包括脑皮层及皮层下白质的异常信号，是目前术前评价FCD的最佳影像检查。

Objective To characterize neuroimaging features of focal cortical dysplasia （FCD） retrospectively and correlate those with pathological findings, which may improve our understanding of neuroimaging characteristics of FCD. Methods Clinical information and neuroimaging findings of 28 cases with FCD proved by pathology were retrospectively reviewed, and neuroimaging features of FCD were correlated with the pathological changes. Results MRI revealed abnormal changes in 24 of 28 patients （85.7%） and no abnormalities were observed in 4 cases. Focal cortical thickening and blurring of the gray- white matter junction were the major features of FCD on MRI. Accompanied abnormal MR signals can also be observed in cortical or subcortical white matter in FCD. The radial band of hyperintensity in subcortical white matter tapering to the ventricle is one of the characteristic features of FCD on MRI. On FDG-PET examination, focal hypometabolism were revealed in 9 of 14 cases （64. 3% ）. Histologically, cortical dyslamination was accompanied by various degrees of dysmorphic neurons and balloon cells in cortical and subcortical areas. Subcortical white matter dysmyelination and spongiotic necrotic changes were found in some cases with FCD. Conclusion High resolution MRI can reveal most of the lesions in FCD,including abnormal changes of cortical and subcortical white matter, which makes MRI the best pre-operation examination for FCD.