Diffusion MRI of the Brain and Susceptibility Weighted Imaging (SWI) in Evaluation of Patients with Acute Stroke

Abstract

Background: Magnetic resonance imaging (MRI) is useful not only in identifying ischemic lesions. Susceptibility-weighted imaging (SWI) is a new magnetic resonance procedure that utilizes the magnetic susceptibility variances of various tissues, such as iron, blood and calcification. The aim of this work was to highlight the role of addition of susceptibility weighted MR images to diffusion weighted images of the brain in diagnosis of cases with acute stroke. 
 Methods: This prospective study included 30 subjects with clinical manifestations of acute stroke. All the subjects underwent history taking, routine laboratory tests, cardiologic assessment by echocardiogram and imaging modalities including non-contrast CT study and MRI of the brain.
 Results: PVS on SWI was found in 23 (76.7%) cases, 6 (20%) cases had macro-hemorrhage (low signals) on SWI, and 1 (3.3%) patient had no SWI findings. DWI showed a sensitivity of (100%) and SWI showed a sensitivity of (96.7%) for detection of infarct All of the 30 (100 %) cases showed hyperintense signals on T2WIs, FLAIR sequences and on DWI and hypointense signals on ADC map.
 Conclusions: SWI is a potential adjunct in those patients for detecting an asymmetric prominent hypointense vessels, positive DWI-SWI mismatch is considered as a marker of infarct expansion and an indicator of the ischemic penumbra.