P003 Clinical relevance of leptomeningeal collateral blood flow on MRI in patients with acute middle cerebral artery occlusion

<h3>Introduction</h3> Poor leptomeningeal collateral blood flow is associated with worse clinical outcome in acute ischemic stroke. <h3>Aim of Study</h3> This study aims to evaluate Clinical relevance of leptomeningeal collateral blood flow on MRI in patients with acute middle cerebral artery occlusion (OMCA). <h3>Methods</h3> 328 acute stroke patients who underwent MRI studies due to OMCA were included. A retrospective analysis of MRI findings on leptomeningeal collateral blood flow in acute stroke patients with OMCA is as follows: negative MRI without leptomeningeal collateral flow (-MRI), positive MRI with delayed contrast-enhancing vessels on contrast-enhanced T1WI (CET1WI) and/or FLAIR hyperintense vessels. The relationship of MRI findings of leptomeningeal collateral blood flow was statistically analyzed by comparing it with clinical results using the Modified Rankin Scale. <h3>Results</h3> MRI findings of leptomeningeal collateral flow in acute stroke patients with OMCA were classified and ranked from poor to good clinical outcome as follows: -MRI (125, 38%), delayed enhanced vessels (62, 19%), FLAIR hyperintense vessels (77, 23%), and both delayed enhanced vessels and FLAIR hyperintense vessels (64, 20%), which were each statistically significant (p &lt; 0.05). <h3>Conclusion</h3> MR imaging of leptomeningeal collateral flow in acute stroke patients with OMCA correlates with clinical outcome. Therefore, it can be used as a prognostic MRI marker in acute stroke patient. <h3>Disclosure of Interest</h3> no.