The Role of Imaging in Acute Ischemic Stroke

Elizabeth Tong, M.D; Qinghua Hou, M.D., Ph.D; Jochen B. Fiebach, M.D; Max Wintermark, M.D., M.A.S.


Neurosurg Focus. 2014;36(1):e3 

In This Article

Abstract and Introduction


Neuroimaging has expanded beyond its traditional diagnostic role and become a critical tool in the evaluation and management of stroke. The objectives of imaging include prompt accurate diagnosis, treatment triage, prognosis prediction, and secondary preventative precautions. While capitalizing on the latest treatment options and expanding upon the "time is brain" doctrine, the ultimate goal of imaging is to maximize the number of treated patients and improve the outcome of one the most costly and morbid disease. A broad overview of comprehensive multimodal stroke imaging is presented here to affirm its utilization.


Stroke is the fourth leading cause of death in the United States. According to the American Heart Association, 795,000 patients experience a new or recurrent stroke each year in the US, and stroke results in 1 of every 19 deaths.[63] Current treatments for acute ischemic stroke include intravenous (IV) tissue plasminogen activator (tPA), endovascular mechanical recanalization, and intraarterial thrombolysis. The number needed to treat for IV tPA to benefit 1 patient is about 7.[47] However, less than 5% of patients with acute stroke receive IV tPA. This is largely due to the narrow time window for treatment (3–4.5 hours for IV tPA,[2,21,72,73,125,155] 6 hours for intraarterial thrombolysis,[92] 8 hours for endovascular mechanical recanalization[159,169,177,193,201]) and delayed presentation to care.[3]

Neuroimaging has become a critical tool in the evaluation and management of patients in whom acute ischemic stroke is suspected. In addition to displaying anatomical structures, the latest neuroimaging techniques can elucidate the underlying hemodynamics and pathophysiology. The goals of comprehensive imaging in patients with acute stroke are to provide prompt accurate diagnosis, facilitate triage, expand treatment cohort, optimize individual outcome, and strategize secondary precautions. Logistically, the best-practice protocol at each institution varies and depends on available imaging modalities, physicians' preferences, intervention capabilities, and time constraints.

This review will briefly discuss the utility of comprehensive imaging in acute stroke. Patients who present with acute stroke symptoms fall into one of 3 broad categories: 1) candidates for IV tPA, 2) candidates for endovascular therapy, and 3) other settings. The following discussion is organized based on these 3 categories.