Berron D, Vieweg P, Hochkeppler A, Pluta J B, Ding S-L, Maass A, Luther A, Xie L, Das S R, Wolk D A, Wolbers T, Yushkevich P A, Düzel E, Wisse L E M
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany; German Center for Neurodegenerative Diseases (DZNE), Site Magdeburg, 39120 Magdeburg, Germany.
German Center for Neurodegenerative Diseases (DZNE), Site Magdeburg, 39120 Magdeburg, Germany.
Neuroimage Clin. 2017 May 26;15:466-482. doi: 10.1016/j.nicl.2017.05.022. eCollection 2017.
Recent advances in MRI and increasing knowledge on the characterization and anatomical variability of medial temporal lobe (MTL) anatomy have paved the way for more specific subdivisions of the MTL in humans. In addition, recent studies suggest that early changes in many neurodegenerative and neuropsychiatric diseases are better detected in smaller subregions of the MTL rather than with whole structure analyses. Here, we developed a new protocol using 7 Tesla (T) MRI incorporating novel anatomical findings for the manual segmentation of entorhinal cortex (ErC), perirhinal cortex (PrC; divided into area 35 and 36), parahippocampal cortex (PhC), and hippocampus; which includes the subfields subiculum (Sub), CA1, CA2, as well as CA3 and dentate gyrus (DG) which are separated by the endfolial pathway covering most of the long axis of the hippocampus. We provide detailed instructions alongside slice-by-slice segmentations to ease learning for the untrained but also more experienced raters. Twenty-two subjects were scanned (19-32 yrs, mean age = 26 years, 12 females) with a turbo spin echo (TSE) T2-weighted MRI sequence with high-resolution oblique coronal slices oriented orthogonal to the long axis of the hippocampus (in-plane resolution 0.44 × 0.44 mm) and 1.0 mm slice thickness. The scans were manually delineated by two experienced raters, to assess intra- and inter-rater reliability. The Dice Similarity Index (DSI) was above 0.78 for all regions and the Intraclass Correlation Coefficients (ICC) were between 0.76 to 0.99 both for intra- and inter-rater reliability. In conclusion, this study presents a fine-grained and comprehensive segmentation protocol for MTL structures at 7 T MRI that closely follows recent knowledge from anatomical studies. More specific subdivisions (e.g. area 35 and 36 in PrC, and the separation of DG and CA3) may pave the way for more precise delineations thereby enabling the detection of early volumetric changes in dementia and neuropsychiatric diseases.
磁共振成像（MRI）的最新进展以及对内侧颞叶（MTL）解剖结构特征和解剖变异性的认识不断增加，为人类MTL更具体的细分奠定了基础。此外，最近的研究表明，在许多神经退行性疾病和神经精神疾病中，早期变化在MTL的较小亚区域中比在整体结构分析中更容易被检测到。在此，我们开发了一种新的方案，使用7特斯拉（T）MRI，并结合了新的解剖学发现，用于手动分割内嗅皮质（ErC）、嗅周皮质（PrC；分为35区和36区）、海马旁皮质（PhC）和海马体；其中海马体包括亚区下托（Sub）、CA1、CA2以及CA3和齿状回（DG），它们由覆盖海马体长轴大部分的终叶通路分隔开。我们提供了详细的说明以及逐片分割，以便于未受过训练但经验更丰富的评分者学习。对22名受试者（年龄19 - 32岁，平均年龄 = 26岁，12名女性）进行了扫描，采用快速自旋回波（TSE）T2加权MRI序列，具有与海马体长轴正交的高分辨率斜冠状切片（平面分辨率0.44×0.44毫米），切片厚度为1.0毫米。扫描由两名经验丰富的评分者进行手动描绘，以评估评分者内和评分者间的可靠性。所有区域的骰子相似性指数（DSI）均高于0.78，评分者内和评分者间可靠性的组内相关系数（ICC）在0.76至0.99之间。总之，本研究提出了一种在7T MRI下对MTL结构进行细粒度和全面的分割方案，该方案紧密遵循解剖学研究的最新知识。更具体的细分（例如PrC中的35区和36区，以及DG和CA3的分离）可能为更精确的描绘铺平道路，从而能够检测痴呆和神经精神疾病中的早期体积变化。
