In Vivo Diffusion Tensor Imaging and Histopathology of the Fimbria-Fornix in Temporal Lobe Epilepsy
In Vivo Diffusion Tensor Imaging and Histopathology of the Fimbria-Fornix in Temporal Lobe Epilepsy
复制标题
DOI：
10.1523/jneurosci.1619-09.2010
复制
发表时间：
2010-01-20
影响因子：
5.3
通讯作者：
Gross, Donald W.
中科院分区：
文献类型：
--
作者：
Concha, Luis;Livy, Daniel J.;Gross, Donald W.
虽然扩散张量成像（DTI）已被广泛用于推断人类大脑白质的微观结构特征，但人类体内DTI与组织学之间的相关性尚未得到证实。颞叶癫痫（TLE）合并内侧颞硬化（MTS）患者的穹窿毡DTI参数异常（相对于没有MTS的TLE患者），这可能代表轴突/髓鞘完整性的差异。医学上难治性TLE患者接受包括穹窿纤维在内的颞叶切除术，为研究新切除组织中水扩散异常的解剖学相关性提供了独特的机会。我们招募了11例难治性TLE患者（6例有MTS， 5例没有MTS）进行术前DTI手术，随后手术切除穹窿纤维的一小块标本，并对其进行电子显微镜处理。显微照片的盲法定量分析包括轴突直径、密度和面积、累积轴突膜周长、髓鞘厚度和面积。DTI预测，TLE合并MTS患者的穹窿毡轴突外部分增加，轴突膜周长和髓鞘面积减少。与动物文献一致，水在穹窿毡脚上的扩散各向异性与手术标本内的轴突膜（累积膜周长）密切相关（与DTI分析的15%相似）。组织学与人体内DTI之间的相关性，结合体内DTI准确预测人类疾病状态下白质异常的观察，为DTI作为白质病理无创标志物的应用提供了强有力的验证。
While diffusion tensor imaging (DTI) has been extensively used to infer micro-structural characteristics of cerebral white matter in human conditions, correlations between human in vivo DTI and histology have not been performed. Temporal lobe epilepsy (TLE) patients with mesial temporal sclerosis (MTS) have abnormal DTI parameters of the fimbria-fornix (relative to TLE patients without MTS) which are presumed to represent differences in axonal/myelin integrity. Medically intractable TLE patients who undergo temporal lobe resection including the fimbria-fornix provide a unique opportunity to study the anatomical correlates of water diffusion abnormalities in freshly excised tissue. Eleven patients with medically intractable TLE were recruited (six with and five without MTS) for presurgical DTI followed by surgical excision of a small specimen of the fimbria-fornix which was processed for electron microscopy. Blinded quantitative analysis of the microphotographs included axonal diameter, density and area, cumulative axon membrane circumference, and myelin thickness and area. As predicted by DTI the fimbria-fornix of TLE patients with MTS had increased extra-axonal fraction, and reduced cumulative axonal membrane circumference and myelin area. Consistent with the animal literature, water diffusion anisotropy over the crus of the fimbria-fornix was strongly correlated with axonal membranes (cumulative membrane circumference) within the surgical specimen (similar to 15% of what was analyzed with DTI). The demonstration of a correlation between histology and human in vivo DTI, in combination with the observation that in vivo DTI accurately predicted white matter abnormalities in a human disease condition, provides strong validation of the application of DTI as a noninvasive marker of white matter pathology.