摘要： 目的 探讨单侧症状性颈动脉狭窄致脑血流灌注降低的空间模式，以及颈动脉狭窄程度与脑血流量的相关关系。方法 采用CTA 与基于动脉自旋标记的灌注多模态成像技术相结合的方法测量颈动脉狭窄程度；基于体素的分析方法观察轻度狭窄组和中至重度狭窄组患者脑血流灌注变化，以及颈动脉狭窄致脑血流灌注改变空间模式；基于兴趣区的方法分析颈动脉狭窄程度与脑血流量变化的关系。结果 22 例单侧（左侧13 例、右侧9 例）症状性颈动脉粥样硬化性狭窄患者中13 例为轻度狭窄、9 例为中至重度狭窄。与轻度狭窄组相比，中至重度狭窄组患者动脉自旋标记显示双侧（患侧显著）顶叶（t = - 2.382, P = 0.014）、额叶（t = - 2.354, P = 0.015）和半卵圆中心（t = - 2.283, P = 0.017）脑血流量降低，且基本位于双侧（患侧显著）分水岭区；与狭窄程度呈负相关的脑血流灌注改变区域也位于双侧（患侧显著）分水岭区（r = - 0.479，P = 0.024）。结论 单侧症状性颈动脉狭窄可以导致以患侧显著的双侧分水岭区脑血流灌注降低，且颈动脉狭窄程度与脑血流量呈负相关关系。

关键词: 颈动脉狭窄, 体层摄影术, X 线计算机, 磁共振成像

Abstract: Objective  To investigate the spatial pattern of cerebral perfusion decrease resulting from symptomatic unilateral carotid artery stenosis and to assess the relationship between degrees of stenosis and cerebral blood flow (CBF).  Methods  CT angiography (CTA) and arterial spin labeling (ASL) MRI cerebral perfusion were performed in 22 patients with symptomatic unilateral carotid artery stenosis. Diagnosis of carotid artery stenosis and measurement of stenosis degrees was performed by using CTA; cerebral perfusion was determined by ASL. Voxel-based analysis (VBA) were applied to observe perfusion changes in patients with mild stenosis and moderate to severe stenosis, and spatial pattern of cerebral perfusion changes caused by carotid artery stenosis. Analysis based on region of interest (ROI) was used to explore the relationship between degrees of stenosis and CBF.  Results  Twenty-two patients with symptomatic unilateral carotid artery stenosis (13 in the left side and 9 in the right) included 13 cases with mild stenosis and 9 cases with moderate to severe stenosis. Compared to those with mild stenosis, patients with moderate to severe stenosis showed reduced CBF in bilateral (especially in the affected side) parietal lobes (t = - 2.382, P = 0.014), frontal lobes (t = - 2.354, P = 0.015) and centrum semiovale (t = - 2.283, P = 0.017), and was basically located in bilateral cerebral watershed area. Furthermore, perfusion in these areas was negatively correlated with the degree of stenosis (r = - 0.479, P = 0.024).  Conclusions  Symptomatic unilateral carotid artery stenosis may result in cerebral perfusion decreases in bilateral (particularly in the affected side) watershed area and cerebral blood flow is negatively correlated with the degree of stenosis.

Key words: Carotid stenosis, Tomography, X-ray computed, Magnetic resonance imaging