1 Reliability of Aortic MRI at 3Tesla in Patients with Acute Cryptogenic Stroke

Objectives — To evaluate a new 3D MRI protocol for the reliable detection of aortic high-risk plaques compared to transesophageal echocardiography (TEE) and to test the reliability of additional MRI in stroke of undetermined etiology. Methods — 74 acute stroke patients were examined by both TEE and MRI at 3Tesla with special regard to aortic high-risk plaques (i.e., ≥4 mm, superimposed thrombi). ECG synchronized pre- and post-contrast T1-weighted 3D imaging (spatial resolution ~1mm3) covering the thoracic aorta was employed. In plaques ≥3 mm, additional 2D T2 imaging and time-resolved (CINE) imaging sequences were performed. Etiology of brain ischemia was classified according to modified TOAST criteria. Aortic high-risk embolic sources detected by MRI in patients with cryptogenic stroke were evaluated. Results — Differences in maximum aortic wall thickness (AWT) for TEE and MRI were not statistically significant for all aortic segments. The overall number of high-risk plaques detected by MRI (n=74) was substantially higher compared to TEE (n=47). Most noticeably, MRI identified aortic high-risk pathologies in 8/26 (30.8%) patient