INSIGNEO Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK.
Department of Mechanical Engineering, The University of Sheffield, Sheffield, UK.
Ann Biomed Eng. 2022 Jun;50(6):740-750. doi: 10.1007/s10439-022-02956-7. Epub 2022 Apr 1.
Assessment of distal cerebral perfusion after ischaemic stroke is currently only possible through expensive and time-consuming imaging procedures which require the injection of a contrast medium. Alternative approaches that could indicate earlier the impact of blood flow occlusion on distal cerebral perfusion are currently lacking. The aim of this study was to identify novel biomarkers suitable for clinical implementation using less invasive diagnostic techniques such as Transcranial Doppler (TCD). We used 1D modelling to simulate pre- and post-stroke velocity and flow wave propagation in a typical arterial network, and Sobol's sensitivity analysis, supported by the use of Gaussian process emulators, to identify biomarkers linked to cerebral perfusion. We showed that values of pulsatility index of the right anterior cerebral artery > 1.6 are associated with poor perfusion and may require immediate intervention. Three additional biomarkers with similar behaviour, all related to pulsatility indices, were identified. These results suggest that flow pulsatility measured at specific locations could be used to effectively estimate distal cerebral perfusion rates, and ultimately improve clinical diagnosis and management of ischaemic stroke.
目前，对缺血性脑卒中后远端大脑灌注的评估只能通过昂贵且耗时的成像程序来实现，这些程序需要注射造影剂。目前缺乏可以更早地指示血流阻塞对远端大脑灌注影响的替代方法。本研究的目的是使用经颅多普勒（TCD）等微创诊断技术来确定适合临床应用的新型生物标志物。我们使用 1D 模型模拟典型动脉网络中的卒中前后速度和血流波传播，利用 Sobol 敏感性分析，并结合高斯过程仿真器，确定与大脑灌注相关的生物标志物。我们表明，右侧大脑前动脉的搏动指数 > 1.6 值与灌注不良有关，可能需要立即干预。还确定了另外三个具有类似行为的额外生物标志物，均与搏动指数有关。这些结果表明，在特定位置测量的血流脉动性可以有效地用于估计远端大脑灌注率，从而最终改善缺血性脑卒中的临床诊断和管理。
