目的 探究磁共振灌注加权成像 (PWI)检查在大脑中动脉(MCA)狭窄中的临 床应用价值。方法 研究对象来源于2016 年6月-2018年6月期间本院收治的单侧MCA 狭窄或闭塞患者，共计100例，经数字减 影血管造影(DSA)检查确定狭窄程度后接 受PWI检查，获取双侧大脑半球各灌注参 数，如脑血流量(CBF)、脑血容量(CBV)、 平均通过时间(MTT)及达峰时间(TTP)，并 进行统计学分析。结果 DSA显示本组轻 度、中度、重度狭窄及闭塞分别有20例、 32例、28例、20例，PWI检出率依次为 85.00%、93.75%、96.43%、100.00%；随 着狭窄程度的增加，PWI异常灌注率明显 增加，差异有统计学意义(P＜0.05)。与 健侧相比，除了轻度狭窄以外，其余患者 患侧CBF明显降低，MTT、TTP明显延长， 差异有统计学意义(P＜0.05)；随着狭窄 程度增加，患侧、健侧CBF明显降低， MTT、TTP明显延长，比较有统计学意义(P ＜0.05)。Pearson相关性分析显示，MAC 狭窄程度与CBF患侧/健侧比值负相关(P ＜0.05)，与MTT患侧/健侧比值、TTP患侧 /健侧比值正相关(P＜0.05)，与CBV患侧/ 健侧比值无相关性(P＞0.05)。结论 灌注 参数与MCA狭窄程度密切相关，PWI检查还 可通过灌注参数的变化反映MCA狭窄患者 血流动力学情况，继而有助于评估病变区 侧枝循环建立情况，为临床干预提供客观 依据。

Objective To explore the clinical value of magnetic resonance perfusion weighted imaging (PWI) in middle cerebral artery (MCA) stenosis. Methods A total of 100 patients with unilateral MCA stenosis or occlusion who were admitted to the hospital from June 2016 to June 2018 were selected as subjects. They were examined with PWI after determining the degree of stenosis by digital subtraction angiography (DSA). Perfusion parameters of bilateral cerebral hemispheres, such as cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP), were analyzed statistically. Results DSA showed that there were 20 cases, 32 cases, 28 cases and 20 cases of mild, moderate, severe stenosis and occlusion, respectively. The detection rates of PWI were 85.00%, 93.75%, 96.43% and 100.00%, respectively. With the aggravation of stenosis, the abnormal perfusion rate of PWI increased significantly (P<0.05). Compared with the healthy side, except for mild stenosis, the CBF of the affected side was significantly decreased, and the MTT and TTP were significantly prolonged (P<0.05). With the aggravation of stenosis, the CBF on the affected side and the healthy side were significantly decreased, MTT and TTP were significantly prolonged (P<0.05). Pearson correlation analysis showed that the degree of MAC stenosis was negatively correlated with the ratio of CBF on healthy/affected side (P<0.05), and positively correlated with the ratio of MTT on healthy/affected side and the ratio of TTP on healthy/affected side (P<0.05). There was no correlation with the ratio of CBV on healthy/affected side (P>0.05). Conclusion Perfusion parameters are closely related to the degree of MCA stenosis. PWI examination can also reflect the hemodynamics of patients with MCA stenosis through changes in perfusion parameters, which helps to assess the establishment of collateral circulation in the diseased area and provides an objective basis for clinical intervention.