Uno Hisakazu, Nagatsuka Kazuyuki, Kokubo Yoshihiro, Higashi Masahiro, Yamada Naoaki, Umesaki Arisa, Toyoda Kazunori, Naritomi Hiroaki
Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan; Department of Internal Medicine, Takarazuka Sanda Hospital, Sanda, Japan.
Department of Neurology, National Cerebral and Cardiovascular Center, Suita, Japan.
J Stroke Cerebrovasc Dis. 2015 May;24(5):1059-64. doi: 10.1016/j.jstrokecerebrovasdis.2014.12.037. Epub 2015 Mar 25.
Experimental studies of transient focal ischemia indicate biphasic detectability of lesions by diffusion-weighted imaging (DWI); poorly detectable phase exists at 1-12 hours after reperfusion. The present study aimed to clarify whether poorly detectable phase also exists in DWI of transient ischemic attack (TIA) patients.
A retrospective study was conducted in 144 consecutive TIA patients who underwent magnetic resonance imaging (MRI) within 2 weeks after carotid TIA. Patients were classified into 9 groups according to time from disappearance of TIA symptoms to DWI: intraischemic period, 0-1 hour, 1-12 hours, 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA.
Lesions were detected in 33 of 144 patients (22.9%). The frequency of positive lesions was 20% in the intraischemic period and 30.8% at 0-1 hour after the end of TIA; it markedly decreased to 8.7% at 1-12 hours after end of TIA. Thereafter, it increased to 21.7%, 30.8%, 36.4%, 37.0%, 38.5%, and 30% at 12-24 hours, 1-2 days, 2-3 days, 3-7 days, 7-10 days, and 10-14 days after the end of TIA, respectively. In 7 patients, MRI was repeated twice, at 1-12 hours and then at 5-13 days after the end of TIA. Lesions were never detected on the first MRI but were clearly demonstrated in 4 of 7 patients on the second MRI.
The detectability of ischemic lesions may be biphasic after TIA as indicated by experimental studies.
短暂性局灶性缺血的实验研究表明，通过扩散加权成像（DWI）对病变的检测具有双相性；再灌注后1 - 12小时存在检测不佳期。本研究旨在明确短暂性脑缺血发作（TIA）患者的DWI中是否也存在检测不佳期。
对144例连续的TIA患者进行回顾性研究，这些患者在颈动脉TIA后2周内接受了磁共振成像（MRI）检查。根据从TIA症状消失到进行DWI的时间，将患者分为9组：缺血期、TIA结束后0 - 1小时、1 - 12小时、12 - 24小时、1 - 2天、2 - 3天、3 - 7天、7 - 10天和10 - 14天。
144例患者中有33例（22.9%）检测到病变。缺血期阳性病变的频率为20%，TIA结束后0 - 1小时为30.8%；TIA结束后1 - 12小时显著降至8.7%。此后，在TIA结束后12 - 24小时、1 - 2天、2 - 3天、3 - 7天、7 - 10天和10 - 14天分别升至21.7%、30.8%、36.4%、37.0%、38.5%和30%。7例患者在TIA结束后1 - 12小时及之后的5 - 13天重复进行了两次MRI检查。首次MRI检查均未检测到病变，但7例患者中的4例在第二次MRI检查中病变清晰显示。
如实验研究所示，TIA后缺血性病变的可检测性可能具有双相性。
