联合应用DWI和MRA诊断急性脑梗死的临床意义

The application of MRA and DWI'S joint inspect to diagnosis of cerebral infarction

目的探讨磁共振弥散成像(diffusion weighted imaging,DWI)与磁共振血管成像(magnetic resonance angiography,MRA)联合应用在急性期脑梗死诊断中的临床意义。方法收集经临床和影像学确诊为急性脑梗死的患者40例,所有患者行常规MRI、DWI及MRA检查,对MRA原始图像进行最大密度投影(maximum intensity projection,MIP)重建。分析DWI显示病灶与MRA血管异常之间的关系。结果 40例患者的DWI图像均显示与临床症状及体征相符的病灶,且病灶具有较高的信号强度和清晰度。其中病灶在前循环25例、后循环8例、前后循环均有7例;MRA检查均获得清晰血管图像,结果显示动脉硬化3例、动脉狭窄或闭塞37例;40例中28例大面积病灶的血管病变阳性率为100%。DWI在前后循环上显示病灶解剖定位均与MRA上血管异常解剖定位有较好的一致性。结论 DWI对急性期脑梗死的灵敏度较高,MRA能清楚地显示颅内大血管狭窄或闭塞。通过DWI和MRA进行结合比较,可同时显示脑实质和脑血管情况,进一步判定责任血管。

Objective To evaluate the application value of MRA and DWI＇S joint inspection in acute cerebral infarction.Methods Forty patients with cerebral infarction were examined with conventional plain MRI,DWI and MRA scan technique.The MRA images were reconstructed to show carotid and intra cerebral arteries.Described the relationship between the lesions on DWI and the abnormal vessels blood on MRA.Results 40 patients were detected the lesions on DWI which were accorded with clinical symptomsand physical signs.The lesions in DWI showed higher signal intensity and distinctness than those on T2WI.MRA showed 3 cases of atherosclerosis,and 37 cases of arterial stenosis or occlusion.All large area lesions on DWI in 28 patients showed abnormal cranial vessels.The position of lesions on DWI in anterior and posterior circulation was accorded with the anatomy of abnormal vessels on MRA.Conclusion DWI is a more reliable imaging method than conventional MRI in detecting ischemic lesions in acute stroke patients（72 h）.MRA can demonstrated stenosis or occlusion of main vessels.DWI conjuncted with MRA can reveal the relationship between lesions and vessels of cerebral infarction simultaneously.