Advanced MR imaging of acute stroke: The University of California at Los Angeles endovascular therapy experience

An intensive early imaging approach using MR imaging before intra-arterial thrombolysis has provided considerable information regarding acute ischemic stroke, including the dynamic aspects of diffusion and perfusion abnormalities. Simple paradigms, such as diffusion-perfusion mismatch, have been transformed into refined models that estimate the extent of ischemic core and penumbra. MR imaging has also been advanced for the detection of intracranial hemorrhage, and may serve as the sole imaging modality before thrombolysis. Angiographic correlation at the time of thrombolysis has provided unique insight, delineating vascular correlates, including the degree of proximal arterial patency with recanalization and the extent of collateral flow. Although multivariate MR imaging models await prospective validation, these models may ultimately be used to optimize selection of ideal thrombolytic candidates.