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CT angiographic source images detect stroke better than nonenhanced CT scans

When a patient is suspected of having suffered a stroke, clinicians need immediate images of the brain to see which blood vessels are affected and how widespread the damage is. The best views of the brain come from diffusion-weighted magnetic resonance imaging (MRI). However, getting those images takes longer; the common, faster alternative to MRI is computed tomography (CT). CT is also more readily available in hospitals, more affordable, and, with CT angiography (images that look at the arteries in the brain and neck), doctors can obtain most of the critical data needed for patient selection for acute stroke treatment, just as with MRI.

A recent study suggests that CT angiographic source images (CTA-SI, which use injected contrast dye to enhance arterial images and are used to create the CT angiography images) are superior to nonenhanced CT (i.e., no dye injected) for early stroke detection and damage assessment. Researchers compared nonenhanced CT scans with CT angiographic source images for 51 patients suspected of having a middle cerebral artery stroke. They found that CT angiographic source images are better at evaluating acute strokes. Further, they suggest that CT angiographic source images are nearly as good as MRI in detecting strokes that affect a large part of the brain.

The study upholds the practice of using CT angiographic source images, in lieu of nonenhanced CT scans alone, to improve the detection of early changes in the brain and predict the damage a stroke will cause. This study was funded in part by the Agency for Healthcare Research and Quality (HS11392).

See "Acute brain infarct: Detection and delineation with CT angiographic source images versus nonenhanced CT scans," by Erica C.S. Camargo, M.D., Ph.D., Karen L. Furie, M.D., M.P.H., Aneesh B. Singhal, M.D., and others in the August 2007 Radiology, 244(2) pp. 541-548.

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