磁共振脑灌注成像在慢性颈内动脉狭窄与闭塞患者中的应用价值

目的探讨磁共振脑灌注成像对单侧慢性颈内动脉(ICA)重度狭窄、闭塞患者中的临床应用价值。方法62例单侧慢性ICA重度狭窄或闭塞患者行磁共振脑灌注加权成像(PWI)检查,计算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。其中14例进行外科或介入治疗,治疗后复查MR脑灌注成像,对治疗前后结果进行比较分析。结果62例ICA慢性重度狭窄或闭塞患者,PWI均发现病变侧脑灌注异常,表现为TTP、rMTT明显延迟,而rCBF正常轻度下降,rCBV正常或轻度增高。病变侧rMTT、TTP、rCBV、与对侧比较有显著性差异(P<0.01),rCBF无显著差异(P<0.05)。40例患者TTP、rMTT延迟累及大脑中动脉分布区和分水岭区,22例仅累及分水岭区。14例患者外科或介入治疗后TTP、rMTT图灌注异常区较治疗前减小(P<0.01),病变侧TTP、rMTT值较治疗前减低(P<0.01)。结论PWI检查能够提供单侧ICA慢性重度狭窄或闭塞患者脑血流动力学受损情况,观察治疗前后脑灌注的改善情况,为评价疗效提供影像学依据。

Application of MR perfusion-weighted imaging in patients with unilateral ICA stenosis or occlusion

Objective To investigate the diagnostic value of MR perfusion-weighted imaging (PWI) in patients with unilateral ICA high-grade stenosis or occlusion. Methods PWI was performed on 62 patients with unilateral ICA high-grade stenosis or occlusion. The cerebral perfusion parameters such as relative cerebral blood flow(rCBF), relative cerebral blood volume(rCBV), relative mean transit time(rMTT) and time to peak(TTP) were calculated.Fourteen cases underwent surgery or interventional therapy.The results of PWI were compared between before and after therapy. Results The abnormal perfusion findings were depicted in 62 patients with ICA high-grade stenosis or occlusion. The abnormal findings of PWI were delayed TTP and rMTT,normal or slightly decreased rCBF,normal or slightly increased rCBV. The values of rCBV, rMTT and TTP had statistically significant difference(P<0.01).Forty cases had involvement of middle cerebral artery territory and border zone on MTT and TTP maps. Twenty-two cases had invovlement of border zone on MTT and TTP maps.In 14 cases receiving therapy, the values and the extents of abnormal perfusion of TTP and rMTT were decreased (P<0.01).Conclusion PWI can demonstrate the abnormal cerebral hemodynamic changes in patients with unilateral ICA high-grade stenosis or occlusion and provide valuable diagnostic and therapeutic information.