Department of Computer Science, Math, Physics, and Statistics, University of British Columbia, Kelowna, British Columbia, Canada.
Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York.
Epilepsia. 2020 Feb;61(2):287-296. doi: 10.1111/epi.16433. Epub 2020 Feb 4.
Vascular structures may play a significant role in epileptic pathology. Although previous attempts to characterize vasculature relative to epileptogenic zones and hippocampal sclerosis have been inconsistent, an in vivo method of analysis would assist in resolving these inconsistencies and facilitate a comparison against healthy controls in a human model. Magnetic resonance imaging is a noninvasive technique that provides excellent soft tissue contrast, and the relatively recent development of susceptibility-weighted imaging has dramatically improved the visibility of small veins.
We built and tested a Hessian-based segmentation technique, which takes advantage of the increased signal and contrast available at 7 T to detect venous structures in vivo. We investigate the ability of this technique to quantify vessels in the brain and apply it to an asymmetry analysis of vessel density in the hippocampus in patients with mesial temporal lobe epilepsy (MTLE) and neocortical epilepsy.
Vessel density was highly symmetric in the hippocampus in controls (mean asymmetry = 0.080 ± 0.076, median = 0.05027), whereas average vessel density asymmetry was greater in neocortical (mean asymmetry = 0.23 ± 0.17, median = 0.14) and MTLE (mean asymmetry = 0.37 ± 0.46, median = 0.26) patients, with the decrease in vessel density ipsilateral to the suspected seizure onset zone. Post hoc testing with one-way analysis of variance and Tukey post hoc test indicated significant differences in the group means (P < .02) between MTLE and the control group only.
Asymmetry in vessel density in the hippocampus is visible in patients with MTLE, even when qualitative and quantitative measures of hippocampal asymmetry show little volumetric difference between epilepsy patients and healthy controls.
血管结构可能在癫痫病理中起重要作用。尽管先前尝试对血管与致痫区和海马硬化的关系进行特征描述的结果并不一致，但采用一种体内分析方法将有助于解决这些不一致，并便于在人类模型中与健康对照进行比较。磁共振成像（MRI）是一种提供出色软组织对比的非侵入性技术，而相对较新的磁化率加权成像的发展极大地提高了小静脉的可视性。
我们构建并测试了一种基于Hessian 的分割技术，该技术利用 7T 时增加的信号和对比度来检测体内静脉结构。我们研究了该技术量化大脑血管的能力，并将其应用于内侧颞叶癫痫（MTLE）和新皮层癫痫患者海马血管密度的不对称性分析。
在对照组中，海马的血管密度高度对称（平均不对称度=0.080±0.076，中位数=0.05027），而新皮层（平均不对称度=0.23±0.17，中位数=0.14）和 MTLE（平均不对称度=0.37±0.46，中位数=0.26）患者的平均血管密度不对称度更大，且血管密度降低的侧与疑似发作起始区相对。单因素方差分析和 Tukey 事后检验的事后检验表明，MTLE 组与对照组之间的组平均值存在显著差异（P<.02）。
即使癫痫患者与健康对照之间的海马不对称性的定性和定量测量显示出很小的体积差异，MTLE 患者的海马血管密度不对称性也是可见的。
