Department of Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea.
Yonsei Med J. 2010 Jul;51(4):590-3. doi: 10.3349/ymj.2010.51.4.590.
Diffusion tensor imaging provides better understanding of pathophysiology of congenital anomalies, involving central nervous system. This study was aimed to specify the pathogenetic mechanism of heterotopia, proved by diffusion tensor imaging, and establish new findings of heterotopia on fractional anisotropy maps.
Diffusion-weighted imaging data from 11 patients (M : F = 7 : 4, aged from 1 to 22 years, mean = 12.3 years) who visited the epilepsy clinic and received a routine seizure protocol MRI exam were retrospectively analyzed. Fractional anisotropy (FA) maps were generated from diffusion tensor imaging of 11 patients with heterotopia. Regions of interests (ROI) were placed in cerebral cortex, heterotopic gray matter and deep gray matter, including putamen. ANOVA analysis was performed for comparison of different gray matter tissues.
Heterotopic gray matter showed signal intensities similar to normal gray matter on T1 and T2 weighted MRI. The measured FA of heterotopic gray matter was higher than that of cortical gray matter (0.236 +/- 0.011 vs. 0.169 +/- 0.015, p < 0.01, one way ANOVA), and slightly lower than that of deep gray matter (0.236 +/- 0.011 vs. 0.259 +/- 0.016, p < 0.01).
Increased FA of heterotopic gray matter suggests arrested neuron during radial migration and provides better understanding of neurodevelopment.
弥散张量成像（DTI）可更好地了解涉及中枢神经系统的先天性畸形的病理生理学。本研究旨在明确弥散张量成像证实的错构瘤的发病机制，并建立错构瘤在各向异性分数（FA）图上的新发现。
回顾性分析了 11 例（男：女=7：4，年龄 1-22 岁，平均 12.3 岁）癫痫患者的弥散加权成像数据，这些患者在癫痫诊所就诊并接受了常规癫痫协议 MRI 检查。从 11 例错构瘤患者的弥散张量成像中生成了 FA 图。在大脑皮质、异位灰质和深部灰质（包括壳核）中放置了感兴趣区（ROI）。对不同灰质组织进行了方差分析（ANOVA）。
异位灰质在 T1 和 T2 加权 MRI 上的信号强度与正常灰质相似。异位灰质的 FA 值高于皮质灰质（0.236±0.011 与 0.169±0.015，p<0.01，单因素方差分析），略低于深部灰质（0.236±0.011 与 0.259±0.016，p<0.01）。
异位灰质的 FA 值升高提示在放射状迁移过程中神经元停滞，这为神经发育提供了更好的理解。
