重新定义TIA的临床和磁共振弥散加权成像的研究

目的通过研究短暂性脑缺血发作（transient ischemicattack，TIA）的临床特征及其与磁共振弥散加权成像（Diffusion-WeightedMRI，DWI）异常改变的关系，进一步探讨TIA新定义在临床中的应用价值。方法以2006年4月-2007年9月在本院住院的TIA患者为研究对象，入选患者完成MRI检查，前瞻性收集其临床资料和检查结果，并分析临床特征与DWI异常的关系。结果共76例TIA患者入选，其中33例（43％）患者DWI异常（阳性）；22例症状持续≥1h的患者中有19例DWI阳性（86％）；症状持续≥1h、有失语、运动障碍的患者DWI阳性率高（P〈0．05）；33例DWI阳性的患者中22例常规MRI也发现相关病灶，但8例是经回顾分析才发现。结论将近一半的TIA患者DWI有急性缺血性病灶；症状持续≥1h、失语和运动障碍与DWI异常有关；新定义有助于TIA的早期评估和治疗，但其部分受限于对影像学检查的依赖。

Reappraise the new definition of TIA with clinical characteristics and Diffusion-Weighted MRI in TIA patients

Objective To assess the clinical characteristics in transient ischemic attack patients and its correlation with Diffusion-Weighted MRI（DWI） abnormolities and further evaluated the clinical application of new defination for TIA. Methods A prospective analysis was performed on all TIA patients who had a MRI scan after symptom onset and entered to hospital during April 2006 -September 2007. The relationship between patients＂ clinical presentation and DWI abnormalities was analyzed. Results DWI-detected abnormalities were present in 33 of 76 cases（43%）. Nineteen of the 22 patients with symptoms lasting equal to or more than 1 hour had DWI lesions. Patients with positive DWI scans were more likely to have symtom duration equal to or more than 1 hour and to have more,aphasia and motor deficits than patients with negative DWI scans. In 22 of 33 cases,a DWI abnormolity was present on both DWI and conventional imaging except that 8 patients were identified retrospectively. Conclusions Nearly half of TIA patients showed acute ischemie lesions on DWI. Symtom duration equal to or more than 1 hour,aphasia and motor deficits are correlated with positive DWI scans. The new definition is useful for rapid evaluation and treatment of patients with TIA, but is limited to its reliance on imaging techniques.