Abstract T P31: Clinical Usefulness of 3D Arterial Spin Labeled Perfusion Image in Acute Ischemic Stroke

Abstract

Purpose: Arterial spin labeled (ASL) perfusion image is a noninvasive imaging method for detecting perfusion deficits and ischemic penumbra in acute ischemic stroke. This method takes additional only few minutes after the routine MRI exam without contrast agent or radioisotope, and is expected to be useful in decision-making for emergent recanalization therapy. It is important to assess the prevalence of diffusion-perfusion mismatch in various stroke types. Here we evaluated the usefulness of the 3D ASL perfusion image in acute ischemic stroke including TIA. Methods: We enrolled 71 consecutive patients (mean 80 years) with acute ischemic stroke from April 2010 to October 2012, who were admitted to the municipal hospital within 24 hours after stroke onset. All patients underwent 3D-ASL perfusion image with the 1.5T MRI scanner in addition to diffusion-weighted image (DWI), FLAIR, T2*, and MRA. We assessed the prevalence of hypoperfusion (none, focal, or diffuse) in 3D-ASL image and the size of diffusion-perfusion mismatch. The associations of these measures with stroke type and lesion size in DWI were also analyzed. Results: Hypoperfusion in ASL image was observed 33% in TIA, 12% in lacunar stroke, 64% in atherosclerotic stroke, and 81% in cardioembolic stroke. Nine patients showed no abnormality in ASL perfusion image, but had arterial transit artifact, which indicates occluded vessel or collateral vessels. Diffusion-perfusion mismatch was most prevalent in patients with middle size of infarction and in patients with atherosclerotic and cardioembolic stroke. 80% of patients who received thrombolytic therapy demonstrated improvement of ASL hypoperfusion. Conclusions: 3D-ASL perfusion image could provide useful clinical information in decision-making for early treatment and their recovery by medical intervention in patients with acute atherosclerotic and cardioembolic stroke.