磁共振扩散加权成像对短暂性脑缺血发作的诊断价值

Diffusion-weighted MR imaging in patients with transient ischemic attack

目的评价短暂性脑缺血发作(TIA)患者磁共振扩散加权成像(DWI)急性缺血病灶发生率,DWI急性缺血病灶和临床特征的关系。方法分析2006年3-10月间在发病后7天内进行常规MRI和DWI检查的126例TIA患者的资料。比较TIA患者DWI表现和临床特征的关系。结果52例TIA患者有DWI急性缺血病灶(52/126,41%)。病灶体积较小(平均体积:1.6cm3),ADC值中度下降(平均ADC比率:76%)。Logistic回归分析显示TIA持续时间大于或等于30min(OR,6.9;95%CI,3.2～23.4),运动障碍(OR,4.8;95%CI,1.9～19.2)和失语(OR,7.8;95%CI,1.9～27.9)是DWI异常的预示因素。52例有DWI异常者中19例在常规MRI上未显示病灶。结论在临床诊断的TIA患者中,近一半有DWI异常,DWI异常与症状持续时间,运动障碍和失语相关。

Objective To evaluate the diagnostic values of diffusion-weighted MRI（DWI）, determine frequency of DWI acute ischemic lesions and the correlation with DWI acute ischemic lesions and clinical factors in patients with transient ischemic attack （TIA）. Methods Clinical, conventional MRI, and DWI data were collected on 126 consecutive patients with TIA between Mar and Oct 2006 within 7 days of symptom onset. The relationship between DWI-detected findings and clinical presentation was then analyzed. Results DWI-detected acute ischemic lesions were present in 52 of 126 cases （52/126, 41%, positive group）. Lesions were small （mean volume： 1.6 cm^3）, and ADC was moderately decreased （mean ADC ratio： 76 %）. A multiple logistic regression model demonstrated that TIA duration greater than or equal to 30 min （OR, 6.9; 95 % CI, 3.2-23.4）, motor deficit （OR, 4.8; 95%CI, 1.9-19.2） and aphasia （OR, 7.8; 95%CI, 1.9-27.9） were independent predictors of DWI lesions. In 19 of 52 cases, the identified lesions not detected by conventional MRI （T2-weighted imaging or fluid-attenuated inversion recovery [FLAIR]）. Conclusion In TIA patients, nearly half with DWI lesions, prolonged TIA duration （TIA duration≥30 minutes）, motor deficits and aphasia were significantly correlated with detecting an abnormality with DWI.