弥散加权成像对短暂性脑缺血发作患者临床转归的诊断价值

The diagnostic value of diffusion weighted imaging in transient ischemic attacks

目的研究TIA患者DWI阳性病灶的意义，对发病后首次DWI检查阳性的TIA患者复查MRI或CT，比较病灶恢复与未恢复患者DWI阳性病灶的表观弥散系数（apparent diffusion coefficient，ADC）、相对表观弥散系数（relative apparent diffusion coefficient，rADC），作为鉴别TIA和脑梗死的依据。方法选择2009年8月到2011年6月包头市中心医院神经内科住院的TIA患者57例，发病24h内行MRI检查，根据检查结果将患者分为DWI阳性组和DWI阴性组；对于DWI阳性患者，7d内复查MRI或CT，将其分为TIA组和脑梗死组，分别比较两组的发病特点及DWI表现，并测量ADC值、rADC值，分析其意义。结果TIA组ADC值（630．4±25．9）×10-3mm2／s，脑梗死组ADC值（495．2±60．0）×10-3mm2／s（t=6．669，P=0．000），TIA组rADC值82．1％±5．6％，脑梗死组rADC值62．6％±7．4％（t=7．013，P=0．000），两组间比较差异有统计学意义。结论TIA组患者DWI病灶ADC值适度下降，而脑梗死组ADC值明显下降，发病早期可以通过比较ADC、rADC值鉴别TIA和脑梗死。

Objective To study the clinical significance of diffusion weighted imaging （DWI） positive lesions in transient ischemic attacks （TIA） patients, TIA patients with fully reversible lesions were compared with the other patients for investigating the predictive value of apparent diffusion coefficient（ADC） for distinguishing between TIA and stroke. Methods Fifty-seven patients hospitalized with TIA at Department of Neurology, Central Hospital of Baotou August 2009 to June 2011 were identified. All patients had brain magnetic resonance imaging within 24 h after onset, then they were divided into DWI positive group and negative group. A follow-up MR imaging or CT was available in patients of DWI positive group. According to MRI or CT, patients were divided into TIA group and cerebral infarction （CI） group. Clinical features and DWI Imaging were compared between the two groups. For each lesion, the quantitative parameters on initial DWI （ADC） were recorded, and comparisons between reversible and irreversible lesions were performed. Results The ADC values were （630. 4±25.9） ×10-3 mm2/s in lesions with TIA and （495.2±60. 0）×10-3 mm2/s with brain infaction （t =6. 669, P =0. 000）. The relative ADC ratio values were lower （62. 6%±7.4% vs 82. 1% ±5.6% , t = 7. 013 ,P = 0. 000） in lesions with subsequent infarct than in those that were fully reversible. Conclusions ADC values are moderately decreased in DWI lesions from TIA patients, while ADC values are significantly decreased in CI group. It is useful to early distinguish TIA from CI by comparing ADC and rADC values.