From the *Department of Neurosurgery, Medical University of Vienna; †High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna and Christian Doppler Laboratory for Clinical Molecular MR Imaging; ‡Department of Clinical Neurology, Medical University of Vienna; §Department of Neurology, General Hospital Hietzing with Neurological Center Rosenhuegel; ∥Institute of Neurology, Medical University of Vienna; ¶Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Austria; and #University Institute for Diagnostic and Interventional Neuroradiology, University Hospital Bern and Inselspital, University of Bern, Bern, Switzerland.
Invest Radiol. 2017 Nov;52(11):666-671. doi: 10.1097/RLI.0000000000000388.
Temporal lobe epilepsy (TLE) is the most frequent form of focal epilepsy in adults. Because approximately half of these patients develop drug resistance, epilepsy surgery designed to remove the epileptogenic zone is an excellent option in selected patients. Histopathological analyses of hippocampal specimens in TLE patients revealed 4 types of Ammon's horn sclerosis, which are correlated with long-term epileptological outcome. The aim of this study was the correlation of noninvasive, high-resolution, morphological magnetic resonance imaging (MRI) at an ultra-high-field (7 T) of the hippocampus in TLE patients with histopathological findings.
High-resolution, T2-weighted FSE MRI in 14 patients with drug-resistant temporal lobe epilepsy was performed on a 7 T Magnetom using a 32-channel coil. Four independent investigators assessed the delineation and semiquantitative evaluation of volume, signal intensity, internal architecture, and overall grading of the hippocampal subfields CA1-4, as well as the presence of the dentate granule cell layer (DGCL), on MRI scans. Results were compared with semiquantitative evaluation of neuronal loss and astrogliosis in the histological sections of the surgical specimens.
Seven-tesla MR examinations were evaluable in 13 cases. Volume loss and signal intensity, as well as overall grading, showed a strong correlation between MRI and histology in individual CA regions. Furthermore, sensitivity and specificity values up to 100% were found for the detection of pathology in the CA subfields. The prediction of Ammon's horn sclerosis type was correct in up to 12 of 13 cases, whereas the dentate gyrus could not be delineated on MRI.
High-resolution, ultra-high-field MRI is a promising tool for the detection of subtle changes in the hippocampus in patients with temporal lobe epilepsy. Large cohorts will be necessary to confirm the predictive value of 7 T MRI in the preoperative evaluation of TLE patients.
颞叶癫痫（TLE）是成人中最常见的局灶性癫痫类型。由于这些患者中约有一半出现药物耐药性，因此针对致痫区的癫痫手术是一种很好的选择，尤其适用于部分特定患者。对 TLE 患者海马标本的组织病理学分析显示存在 4 种 Ammon 角硬化类型，这些类型与长期癫痫学结果相关。本研究旨在探讨 TLE 患者海马的高分辨率、超高场（7T）磁共振成像（MRI）的非侵入性、形态学与组织病理学发现之间的相关性。
采用 32 通道线圈，在 7T Magnetom 磁体上对 14 例药物难治性颞叶癫痫患者进行高分辨率、T2 加权 FSE MRI 检查。4 位独立的研究者评估了 MRI 扫描中海马 CA1-4 亚区的边界和半定量评估、体积、信号强度、内部结构和整体分级，以及齿状回颗粒细胞层（DGCL）的存在。结果与手术标本组织学切片中神经元丢失和星形胶质增生的半定量评估进行了比较。
13 例患者的 7T 磁共振检查可评估。个体 CA 区域的 MRI 和组织学之间的体积损失和信号强度以及整体分级显示出很强的相关性。此外，在 CA 亚区检测病理学的灵敏度和特异性值高达 100%。在 13 例病例中，有 12 例预测 Ammon 角硬化类型是正确的，而 MRI 无法描绘出齿状回。
高分辨率、超高场 MRI 是一种有前途的工具，可用于检测颞叶癫痫患者海马的细微变化。需要更大的队列来证实 7T MRI 在 TLE 患者术前评估中的预测价值。
