Pu Yuehua, Lan Linfang, Leng Xinyi, Wong Lawrence Ks, Liu Liping
1 Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
2 Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Hong Kong SAR, China.
Int J Stroke. 2017 Apr;12(3):236-245. doi: 10.1177/1747493016685716. Epub 2017 Jan 9.
Background Intracranial atherosclerotic stenosis is an important etiology subtype of ischemic stroke. Stenosis severity was thought to be the main reference index for clinical treatment and research. However, stenosis could not reflect the ischemia risk completely, instead the hemodynamic state across the lesion, the extent of collateral circulation, and perfusion impairment downstream the stenosis are more important. Aims We write this review aimed to summarize novel angiographic methods applied in the evaluation of functional severity of ICAS, and commented on their limitations and prospects in future research. Summary of review The main methods to estimate cerebral blood flow including fractional flow assessed by signal intensity ratio, computational fluid dynamics analysis or pressure wire, quantitative magnetic resonance angiography. Fractional flow as a series cerebral hemodynamic parameters may reflect the status of collateral circulation and cerebral blood flow. But the accuracy of the methods was not validated. The method to calculate fractional flow reserve in cardiovascular disease cannot duplicate in cerebrovascular disease. Fractional flow measurement by floating a pressure guidewire across the intracranial stenosis was technically feasible and safe. In the future researches, a non-invasive method should be established to identify high-risk intracranial lesions and may help in decision-making. Conclusions The relationship between stenosis and cerebral blood flow was individualized. Cerebral hemodynamic criteria should be used to screen patients to endovascular treatment, which will optimize the diagnosis and treatment strategies for patients with symptomatic intracranial artery stenosis.
颅内动脉粥样硬化性狭窄是缺血性卒中的重要病因亚型。狭窄程度曾被认为是临床治疗和研究的主要参考指标。然而，狭窄并不能完全反映缺血风险，相反，病变部位的血流动力学状态、侧支循环范围以及狭窄下游的灌注损伤更为重要。目的：撰写本综述旨在总结应用于评估颅内动脉粥样硬化性狭窄功能严重程度的新型血管造影方法，并对其在未来研究中的局限性和前景进行评述。综述总结：评估脑血流量的主要方法包括通过信号强度比评估的分流分数、计算流体动力学分析或压力导丝、定量磁共振血管造影。分流分数作为一系列脑血流动力学参数，可能反映侧支循环状态和脑血流量。但这些方法的准确性尚未得到验证。心血管疾病中计算分流分数储备的方法无法在脑血管疾病中复制。通过将压力导丝漂浮穿过颅内狭窄来测量分流分数在技术上是可行且安全的。在未来研究中，应建立一种非侵入性方法来识别颅内高危病变，并可能有助于决策制定。结论：狭窄与脑血流量之间的关系是个体化的。应使用脑血流动力学标准来筛选适合血管内治疗的患者，这将优化有症状颅内动脉狭窄患者的诊断和治疗策略。
