Wang Hao, Han Xue, Li Mingan, Yang Zheng-Han, Liu Wen-Hu, Wang Zhen-Chang
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Department of Nephrology, Faculty of Kidney Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
Quant Imaging Med Surg. 2022 Jan;12(1):341-353. doi: 10.21037/qims-20-1246.
Hemodialysis (HD) causes various nervous system abnormalities. Alterations in white matter (WM) microstructure after long-term HD have been reported in a few previous studies; however, no studies have been performed to investigate enlarged perivascular spaces (PVS) in WM regions. We measured cerebral blood flow (CBF) and white matter volume (WMV) in HD patients to assess enlarged PVS severity in the WM across the whole brain and suggest possible explanations for this.
Fifty-one HD patients and 51 age-, sex-, and education-matched healthy controls (HCs) were recruited. The number of enlarged PVS in the centrum semiovale (CS), cerebral watershed (CW), and basal ganglia (BG) regions were assessed by T2-weighted MRI. CBF was estimated by arterial spin labeling (ASL), which is a non-invasive perfusion imaging technique. WMV was assessed by the computational anatomy toolbox (CAT12), which is a statistical analysis package. Differences in descriptive variables (two-tailed -tests, χ tests, Mann-Whitney U tests, and Friedman M tests), an intra-class correlation between radiologists, the relationship between enlarged PVS number and HD duration, normalized CBF and WMV (multiple regression), and group differences in CBF and WMV {voxel-wise -tests with age and sex as covariates [cluster size >50 voxels, false discovery rate (FDR) corrected, P<0.05]} were assessed.
HD patients displayed a more significant number of CS-PVS and CW-PVS in WM regions compared with the HCs, but there was no significant difference in the number of BG-PVS. The number of CS-PVS and CW-PVS were positively associated with HD duration. The number of CW-PVS was positively associated with CBF changes and WMV alteration in HD patients. Meanwhile, significant differences in the blood pressure (BP) readings pre-HD, intra-HD, and post-HD were observed in HD patients. Compared with the HCs, the HD patients showed higher CBF in the CS, CW, and BG regions (P<0.05). Hence, decreased WMV in the CS, CW, and BG regions were shown in the HD patients compared with the HCs (P<0.05).
Enlarged CS-PVS and CW-PVS on MRI might be a feature of long-term HD patients. Enlarged CW-PVS number is associated with higher CBF in the CW region and lower WMV in the CW region in HD patients.
血液透析（HD）会引发各种神经系统异常。先前已有少数研究报道了长期血液透析后白质（WM）微观结构的改变；然而，尚未有研究对WM区域的血管周围间隙（PVS）扩大情况进行调查。我们测量了HD患者的脑血流量（CBF）和白质体积（WMV），以评估全脑WM中PVS扩大的严重程度，并对此提出可能的解释。
招募了51例HD患者和51名年龄、性别及教育程度相匹配的健康对照者（HCs）。通过T2加权磁共振成像（MRI）评估半卵圆中心（CS）、脑分水岭（CW）和基底节（BG）区域扩大的PVS数量。采用动脉自旋标记（ASL）估计CBF，ASL是一种非侵入性灌注成像技术。通过计算解剖学工具箱（CAT12）评估WMV，CAT12是一个统计分析软件包。评估描述性变量的差异（双侧t检验、χ检验、曼-惠特尼U检验和弗里德曼M检验）、放射科医生之间的组内相关性、扩大的PVS数量与HD持续时间之间的关系、标准化CBF和WMV（多元回归）以及CBF和WMV的组间差异{以年龄和性别作为协变量的体素级t检验[簇大小>50体素，错误发现率（FDR）校正，P<0.05]}。
与HCs相比，HD患者WM区域的CS-PVS和CW-PVS数量更多，但BG-PVS数量无显著差异。CS-PVS和CW-PVS的数量与HD持续时间呈正相关。HD患者中，CW-PVS的数量与CBF变化和WMV改变呈正相关。同时，观察到HD患者透析前、透析中和透析后的血压（BP）读数存在显著差异。与HCs相比，HD患者CS、CW和BG区域的CBF更高（P<0.05）。因此，与HCs相比，HD患者CS、CW和BG区域的WMV降低（P<0.05）。
MRI上CS-PVS和CW-PVS扩大可能是长期HD患者的一个特征。HD患者中，CW-PVS数量增加与CW区域较高的CBF和较低的WMV相关。
