The role of neuroimaging in selecting treatments for patients with acute stroke.

The armamentarium available for treating acute stroke patients is growing as clinical trials show benefit of intravenous thrombolysis, intra-arterial clot lysis, and antiplatelet agents. Patients with dissection or severe atheromatous stenosis of major cerebrovascular vessels are commonly treated with anticoagulation to prevent recurrent artery-to-artery embolus or arterial thrombosis. These advances in acute stroke treatments demand an accurate means to quickly identify those patients most likely to benefit (or not benefit) from a specific therapy. Fortunately, advances in imaging cerebrovascular lesions, decreased brain perfusion, and even ischemic tissue injury now make it possible to consider tailoring therapy to the individual patient's cerebrovascular problem. Experience and controlled clinical data in this endeavor is meager. Here we describe the ability of various emergency neuroimaging tools to provide information on the state of brain blood flow, metabolism, and vascular anatomy. Most importantly, we present the rationale and limited available evidence relevant to how the neuroimaging information might be used to select optimal treatments for individual patients.