Abstract 2753: Initial and 24h After Admisson DWI Can Predict Recurrence of Ischemic Event of TIA Patients

Background and Purpose Our aim is to investigate the diagnostic utility of diffusion weighted magnetic resonance imaging (DWI) for transient ischemic attack (TIA), not only admission but also 24 h after first study. Methods We prospectively enrolled TIA patients who were admitted within 24 h of onset. We examined trans-thoracic echocardiography, 24 h Holter electrocardiography, and carotid duplex ultrasonography in order to give the best medication. All of patients received DWI immediately after admission. At first, when we observed hyper-intense lesion considered as ischemia, additional DWI examination was not conducted. When there was no hyper-intense lesion on initial DWI study, we conducted follow-up DWI 24 h after initial examination. We defined a recurrence of ischemic event as an occurrence of symptomatic ischemic stroke or TIA at 3 months after onset. Regarding initial DWI study, we compared proportional frequency of recurrence between patients with ischemic lesion (i-positive group) and without any lesion (i-negative group), and also compared recurrence rate between patients with ischemic lesion on initial and/or follow-up studies (if-positive group) and without any lesion on both studies (if-negative group). Results We registered 100 TIA patients (men; 63, median age; 74 years, ABCD2 score <3; 32). On initial DWI study, 34 patients had ischemic lesion (i-positive group) and 66 had no lesion (i-negative group). Among 66 patients of i-negative group, 12 (19%) had hyper-intense lesion in follow-up study. Finally, there were 46 patients in if-positive group and 54 in if- negative. Recurrence ischemic event occurred in 19 (19%) of 100 patients. There was no significant difference of recurrence rate between i-positive and i-negative groups (27% vs. 16%, p=0.172). However, recurrence rate was significantly higher in if-positive group than these of if-negative group (29% vs. 12%, p=0.024) Conclusions New ischemic lesions on follow up DWI appeared in approximately 20% of TIA patients who did not have ischemic lesion on initial DWI. Only initial DWI but initial and follow-up DWI was important role of predicting the recurrence of ischemic events in TIA patients.