多重灌注成像技术在缺血性脑血管疾病中的应用

Application of multiple perfusion imaging in ischemic cerebrovascular disease

目的:探讨伪连续式动脉自旋标记(PCASL)灌注成像与动态磁敏感对比(DSC)灌注成像在缺血性脑血管疾病中的诊断价值。方法:对26例临床拟诊为脑缺血患者行常规MRI、DWI、PCASL及DCS-PWI扫描。参照DWI图像,分别测量PCASL与DSC图像上缺血病灶(ROI)的脑血流量(CBF)值及对侧镜像部位CBF值;记录灌注异常的形式(低/高灌注)、部位及范围。结果:26例中,经临床随诊证实脑梗死21例,短暂性脑缺血发作(TIA)5例。21例脑梗死中,19例2种方法灌注表现一致(低灌注16例,高灌注3例),行Kappa检验,一致性较好;16例低灌注中,14例PCASL的CBF值均低于DSC(P<0.05)。5例TIA中,4例灌注表现一致(低灌注3例,高灌注1例),1例不符,两者行Kappa检验,一致性较好。结论:PCASL与DSC显示梗死病灶灌注状态具有较高的一致性,在显示低灌注病灶方面PCASL较DSC更敏感。

Objective:To evaluate the value of pseudo continuous arterial spin labeling perfusion imaging(PCASL)and dynamic contrast enhanced magnetic perfusion imaging(DSC)in the diagnosis of ischemic cerebrovascular disease.Methods:Routine MRI,DWI,ASL and DCS-PWI scans were performed in 27 patients with clinically diagnosed cerebral infarction,refer to the DWI image,infarct size(ROI)CBF value and CBF value of contralateral mirror site were measured on PCASL and DSC respectively.The location,size,extent,and ischemic penumbra(IP)of the perfusion abnormalities were recorded.Results:26 cases of cerebral infarction,clinical follow-up confirmed 21 cases of cerebral infarction and 5 cases of TIA.In 21 cases of cerebral infarction,19 cases were consistent with perfusion of two methods(16 cases with low perfusion,3 cases with high perfusion),and both of them were tested by kappa,and the agreement was good.In 16 cases of low perfusion,the PCASL-CBF values of 14 cases were lower than the DSC-CBF value,and the difference was statistically significant by paired data t test(P<0.05).In 5 cases of TIA,4 cases were consistent with perfusion(3 cases with low perfusion,1 case with high perfusion),1 case was not matched,and the kappa test was performed by both.Conclusions:PCASL and DSC show a high consistency in perfusion status of infarct lesions,PCASL is more sensitive than DSC in showing hypoperfusion.Combination of DWI with ischemic penumbra is of clinical value,and ASL is helpful for the early diagnosis of TIA.