A Diffeomorphic Vector Field Approach to Analyze the Thickness of the Hippocampus From 7 T MRI.
A Diffeomorphic Vector Field Approach to Analyze the Thickness of the Hippocampus From 7 T MRI.
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基于同构向量场的7T MRI海马厚度分析。
DOI：
10.1109/tbme.2020.2999941
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Colliot O
中科院分区：
文献类型：
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作者：
Guyot A;Fouquier ABG;Gerardin E;Chupin M;Glaunes JA;Marrakchi-Kacem L;Germain J;Boutet C;Cury C;Hertz-Pannier L;Vignaud A;Durrleman S;Henry TR;van de Moortele PF;Trouve A;Colliot O
7-海马的特斯拉MRI增强了其内部亚结构的可视化。在这些亚结构中，氨角和下托形成一个连续的灰质折叠带。在这里，我们提出了一种方法来分析这种带的局部厚度测量。我们介绍了一个原始的方法的基础上估计的一个超纯向量场，穿过丝带。该方法旨在处理海马体和相应的7特斯拉采集的特异性：高度复杂的表面，非封闭的带状，不完全定义的内/外边界，各向异性采集。此外，我们建议进行群体比较，使用人口模板建立从中央表面的个别科目。我们首先评估了我们的方法的鲁棒性，各向异性，以及评价者间的变异性，在死后扫描和体内采集分别。然后，我们对颞叶癫痫（TLE）患者和健康对照者的体内MRI数据集进行了分组研究。该方法检测到患者的局部变薄模式，主要是癫痫发作病灶的同侧，这与医学知识一致。这项新技术允许从7特斯拉MRI测量海马体的厚度。它在各向异性和评分者间变异性方面显示出良好的鲁棒性，并有可能检测患者的局部萎缩。随着7特斯拉MRI越来越可用，这种新方法可能成为研究大脑疾病中海马体局部变化的有用工具。社区可以免费获得它（代码：https：//github.com/aramis-lab/hiplay7-thickness，事后分割：https：//doi.org/10.5281/zenodo.3533264）。
7-Tesla MRI of the hippocampus enhances the visualization of its internal substructures. Among these substructures, the cornu Ammonis and subiculum form a contiguous folded ribbon of gray matter. Here, we propose a method to analyze local thickness measurements of this ribbon. We introduce an original approach based upon the estimation of a diffeomorphic vector field that traverses the ribbon. The method is designed to handle specificities of the hippocampus and corresponding 7-Tesla acquisitions: highly convoluted surface, non-closed ribbon, incompletely defined inner/outer boundaries, anisotropic acquisitions. We furthermore propose to conduct group comparisons using a population template built from the central surfaces of individual subjects. We first assessed the robustness of our approach to anisotropy, as well as to inter-rater variability, on a post-mortem scan and on in vivo acquisitions respectively. We then conducted a group study on a dataset of in vivo MRI from temporal lobe epilepsy (TLE) patients and healthy controls. The method detected local thinning patterns in patients, predominantly ipsilaterally to the seizure focus, which is consistent with medical knowledge. This new technique allows measuring the thickness of the hippocampus from 7-Tesla MRI. It shows good robustness with respect to anisotropy and inter-rater variability and has the potential to detect local atrophy in patients. As 7-Tesla MRI is increasingly available, this new method may become a useful tool to study local alterations of the hippocampus in brain disorders. It is made freely available to the community (code: https://github.com/aramis-lab/hiplay7-thickness, post-mortem segmentation: https://doi.org/10.5281/zenodo.3533264).