慢性大脑中动脉狭窄与闭塞的MR灌注成像研究

Study of MR Perfusion-weighted Imaging in Patients with Chronic MCA Stenosis or Occlusion

目的探讨单侧大脑中动脉(MCA)慢性重度狭窄、闭塞患者的MR脑灌注成像表现及其应用价值。方法28例单侧MCA慢性重度狭窄或闭塞患者行MR脑灌注成像检查,得出有关脑灌注参数图,包括相对脑血流量(rCBF)、相对脑血容量(rCBV)、相对平均通过时间(rMTT)和达峰时间(TTP)图,对灌注成像表现进行定性和定量分析。结果28例MCA慢性重度狭窄或闭塞患者,磁共振灌注加权成像(PWI)均发现病变侧灌注异常,病变侧rCBV、rMTT和TTP与对侧比较差异有显著性意义(P<0.01),rCBF差异无显著性意义(P>0.05)。rMTT和TTP图显示病变侧较对侧明显延迟,24例仅累及MCA供血区,4例同时累及MCA和分水岭区。结论PWI检查能够显示单侧MCA慢性重度狭窄或闭塞患者脑血流动力学受损情况,对临床诊断和治疗具有重要价值。

Objective：To investigate the diagnostic value of MR perfusion-weighted imaging （PWI） in patients with severe unilateral middle cerebral artery （MCA） chronic stenosis or occlusion. Methods：PWI was performed in 28 patients with severe unilateral MCA stenosis or occlusion. The cerebral perfusion parameters included rCBF, rCBV, rMTT and TTP of the occluded as well as the contralateral hemisphere. These values were calculated,and the qualitative as well as quantitative analysis were carried out. Results： Of the 28 patients with severe MCA stenosis or occlusion, the rCBV, rMTT and TTP values showed statistically significant difference （P〈0.01） of abnormal regions between the occluded and the contralateral hemisphere. However,the rCBF values showed no statistically significant difference （P〉0.05）. The rMTT and TTP were significantly delayed on the occluded side. In 24 cases,only the MCA supplied territory were involved;in 4 cases the MCA supplied territory as well as the border zone were involved. Conclusion ：The abnormal cerebral hemodynamic changes in patients with unilateral severe MCA stenosis or occlusion can be demonstrated by PWI.