Acute MRI in Transient Ischemic Attack

The purpose of this study is to detect acute ischemic lesions in patients admitted with symptoms of transient ischemic attack (TIA). Diffusion weighted Imaging (DWI) is today one of the best ways to detect ischemic lesions after TIA. The problem is that this only gives the diagnosis in 30% of the cases. It is possible that the addition of ASL-perfusion imaging and diffusion tensor imaging will make it possible to give a more accurate and selective diagnosis of TIA. Patients admitted with clinical signs of TIA can be included. Patients will be examined with the TIA protocol in reference to the standardized clinical care: 1. 1,5 tesla gradient echo and 3 tesla Susceptibility weighted imaging (SWI) to detect microbleed as sign of small vessel disease. 2. Axial T2 FLAIR to detect white matter lesions. 3. Axial DWI to detect areas with impeded diffusion. (Total scantime 10min) If no signs of ischemic lesions is detected the following additional research scan-protocol will be initiated: 1. Perfusion without contrast: Arterial spin labeling (ASL) with the ability of showing signs of ischemia. 2. Diffusion tensor imaging (DTI): Has a higher sensitivity than DWI in displaying local ischemic lesions. (Total additional scantime 10min) All in All 20min in the scanner.