Lee Sang Hun, Nah Hyun Wook, Kim Bum Joon, Ahn Sung Ho, Kim Jong S, Kang Dong Wha, Kwon Sun U
Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Department of Neurology, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea.
J Clin Neurol. 2017 Apr;13(2):129-137. doi: 10.3988/jcn.2017.13.2.129. Epub 2017 Jan 12.
The absence of acute ischemic lesions in diffusion-weighted imaging (DWI) in transient ischemic attack (TIA) patients makes it difficult to diagnose the true vascular etiologies. Among patients with DWI-negative TIA, we investigated whether the presence of a perfusion-weighted imaging (PWI) abnormality implied a true vascular event by identifying new acute ischemic lesions in follow-up magnetic resonance imaging (MRI) in areas corresponding to the initial PWI abnormality.
The included patients underwent DWI and PWI within 72 hours of TIA and also follow-up DWI at 3 days after the initial MRI. These patients had visited the emergency room between July 2009 and May 2015. Patients who demonstrated initial DWI lesions were excluded. The initial PWI abnormalities in the corresponding vascular territory were visually classified into three patterns: no abnormality, focal abnormality, and territorial abnormality.
No DWI lesions were evident in initial MRI in 345 of the 443 TIA patients. Follow-up DWI was applied to 87 of these 345 DWI-negative TIA patients. Initial PWI abnormalities were significantly associated with follow-up DWI abnormalities: 8 of 43 patients with no PWI abnormalities (18.6%) had new ischemic lesions, whereas 13 of 16 patients with focal perfusion abnormalities (81.2%) had new ischemic lesions in the areas of initial PWI abnormalities [odds ratio (OR)=15.1, 95% confidence interval (CI)=3.6-62.9], and 14 of 28 patients with territorial perfusion abnormalities (50%) had new lesions (OR=3.7, 95% CI=1.2-11.5).
PWI is useful in defining whether or not the transient neurological symptoms in DWI-negative TIA are true vascular events, and will help to improve the understanding of the pathomechanism of TIA.
短暂性脑缺血发作（TIA）患者的弥散加权成像（DWI）未显示急性缺血性病变，这使得诊断真正的血管病因变得困难。在DWI阴性的TIA患者中，我们通过在后续磁共振成像（MRI）中识别与初始灌注加权成像（PWI）异常相对应区域的新急性缺血性病变，来研究PWI异常的存在是否意味着真正的血管事件。
纳入的患者在TIA发作72小时内接受了DWI和PWI检查，并在初始MRI检查3天后接受了随访DWI检查。这些患者于2009年7月至2015年5月期间就诊于急诊室。表现出初始DWI病变的患者被排除。将相应血管区域的初始PWI异常在视觉上分为三种类型：无异常、局灶性异常和区域异常。
443例TIA患者中，345例初始MRI未发现DWI病变。对这345例DWI阴性的TIA患者中的87例进行了随访DWI检查。初始PWI异常与随访DWI异常显著相关：43例无PWI异常的患者中有8例（18.6%）出现了新的缺血性病变，而16例局灶性灌注异常的患者中有13例（81.2%）在初始PWI异常区域出现了新的缺血性病变[比值比（OR）=15.1，95%置信区间（CI）=3.6-62.9]，28例区域灌注异常的患者中有14例（50%）出现了新病变（OR=3.7，95%CI=1.2-11.5）。
PWI有助于确定DWI阴性的TIA患者的短暂性神经症状是否为真正的血管事件，并将有助于提高对TIA发病机制的理解。
