Department of Neurology, Key Laboratory of Developmental Genes and Human Disease, Affiliated ZhongDa Hospital, School of Medicine, Institution of Neuropsychiatry, Southeast University, Nanjing, Jiangsu 210009, China.
Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China.
Comput Methods Programs Biomed. 2022 Jan;213:106497. doi: 10.1016/j.cmpb.2021.106497. Epub 2021 Oct 24.
Cerebral hemodynamic disorders are involved in the occurrence and progression of vascular dementia (VaD), but the methods to detect hemodynamics remainmultifarious and uncertain nowadays. We aim to exploit a computational fluid dynamics (CFD) approach by static and dynamic parameters, which can be used to detect individual cerebrovascular hemodynamics quantitatively.
A patient-specific CFD model was constructed with geometrical arteries on the magnetic resonance angiography (MRA) and hemodynamic parameters on ultrasound Doppler, by which, the structural and simulated hemodynamic indexes could be obtained, mainly including the cerebral arterial volume (CAV), the number of visible arterial outlets, the total cerebral blood flow (tCBF) index and the total cerebrovascular resistance (tCVR) index. The hemodynamics were detected in subcortical vascular dementia (SVaD) patients (n = 38) and cognitive normal controls (CNCs; n = 40).
Compared with CNCs, the SVaD patients had reduced outlets, CAV and tCBF index (all P ≤ 0.001), increased volume of white matter hyperintensity (WMH) and tCVR index (both P ≤ 0.01). The fewer outlets (OR = 0.77), higher Hachinski ischemic score (HIS) (OR = 3.65), increased tCVR index (OR = 1.98) and volume of WMH (OR = 1.12) were independently associated with SVaD. All hemodynamic parameters could differentiate the SVaD patinets and CNCs, especially the composite index calculated by outlets, tCVR index and HIS (AUC = 0.943). Fewer outlets and more WMH increased the odds of SVaD, which were partly mediated by the tCBF index (14.4% and 13.0%, respectively).
The reduced outlets, higher HIS and tCVR index may be independent risk factors for the SVaD, and a combination of these indexes can differentiate SVaD patients and CNCs reliably. The tCBF index potentially mediates the relationships between hemodynamic indexes and SVaD. Although all simulated indexes only represented the true hemodynamics indirectly, this CFD model can provide patient-specific hemodynamic alterations non-invasively and conveniently.
脑血流动力学障碍参与血管性痴呆（VaD）的发生和发展，但目前检测血流动力学的方法仍然多种多样，不确定。我们旨在通过静态和动态参数利用计算流体动力学（CFD）方法，以定量检测个体脑血管的血流动力学。
使用磁共振血管造影（MRA）上的几何动脉和超声多普勒上的血流动力学参数构建患者特定的 CFD 模型，通过该模型可以获得结构和模拟的血流动力学指标，主要包括脑动脉容积（CAV）、可见动脉出口数量、总脑血流量（tCBF）指数和总脑血管阻力（tCVR）指数。在皮质下血管性痴呆（SVaD）患者（n=38）和认知正常对照组（CNC；n=40）中检测血流动力学。
与 CNC 相比，SVaD 患者的出口、CAV 和 tCBF 指数降低（均 P≤0.001），脑白质高信号（WMH）体积和 tCVR 指数增加（均 P≤0.01）。出口较少（OR=0.77）、Hachinski 缺血评分（HIS）较高（OR=3.65）、tCVR 指数增加（OR=1.98）和 WMH 体积增加（OR=1.12）与 SVaD 独立相关。所有血流动力学参数均可区分 SVaD 患者和 CNC，尤其是出口、tCVR 指数和 HIS 计算的综合指数（AUC=0.943）。出口较少和 WMH 较多会增加 SVaD 的可能性，其中 tCBF 指数分别解释了 14.4%和 13.0%的可能性。
出口较少、HIS 较高和 tCVR 指数可能是 SVaD 的独立危险因素，这些指数的组合可以可靠地区分 SVaD 患者和 CNC。tCBF 指数可能介导血流动力学指标与 SVaD 之间的关系。尽管所有模拟指标仅间接代表真实的血流动力学，但这种 CFD 模型可以无创且方便地提供患者特定的血流动力学变化。
