早期弥散加权成像阴性的急性缺血性脑卒中4例分析及文献复习

Analysis on early negative diffusion-weighted imaging in 4 cases with acute ischemic stroke and a review of literatures

目的探讨磁共振(MRI)早期弥散加权成像(DWI)阴性的急性缺血性卒中患者的临床特点、影像学表现及病因,提高对急性缺血性脑卒中早期DWI假阴性这一现象的认识。方法回顾分析2015~2016年间住院的4例磁共振早期弥散加权成像阴性的急性缺血性脑卒中患者的临床表现及影像学特点。结果 4例患者中男性2例,女性2例。起病年龄为34~79岁。头颅MRI检查时间为起病后1~7天。临床诊断2例患者为前循环缺血性卒中可能性大,1例患者考虑为后循环缺血性卒中可能。另外1例患者首次MRI阳性的病灶位于后循环供血区,而早期DWI阴性的病灶为前循环供血区。NIHSS评分在2~7分之间,属于轻型卒中。结论早期的DWI阴性并不能完全除外急性缺血性脑卒中的诊断。这种现象在前后循环的病变以及不同发病机制的患者中均可以见到。但更多见于轻型卒中患者。可以结合多种模式的影像学检查或者复查来提高确诊率,以免延误诊治。

Objective To explore the clinical characteristics of cases of acute ischemic stroke with early false-negative diffusion-weighted MR imaging,manifestations of features of imaging and etiology,in order to raise the level of early diagnosis of this kind of disease. Methods The medical records of 4 patients with acute ischemic stroke without early-DWI findings during 2015 to 2016 were retrospectively reviewed and analyzed. Their clinical manifestations,MRI findings and the possible pathogenesis were analyzed. Results There were two males and two females in these patients. The age range of patients was among 34 to 79 years old. The MRI latency（ the delayed period from onset of symptoms to initial MRI scanning） was 1 - 7 days. According to clinical diagnosis,the stroke lesions located in anterior circulation in 2 patients and the lesion located in posterior circulation in 1 patient. Stroke lesion in posterior circulation was clearly visible in the initial MR images but another lesion was located in anterior circulation,and it was overlooked in the last patient. The National Institute of Health Stroke Scale（ NIHSS） scores on the admission were between 2 to 7. Conclusion The pathogenesis of stroke can be observed both in association with the posterior circulation and anterior circulation. This phenomenon often occurs in minor stroke. Multi-model imaging and follow-up MRI scanning may be important.