BETHESDA, Md., Jan. 26 (UPI) -- Magnetic resonance imaging works better than computed tomography for emergency diagnosing of acute ischemic stroke, says a U.S. study.
MRI appears to be a more sensitive test than CT for such screening, said researchers at the National Institute of Neurological Disorders and Stroke, a part of the National Institutes of Health.
Acute ischemic stroke is the most common form of stroke and is caused by a blood clot. The researchers said their finding also holds true for diagnosing a second type of stroke, hemorrhagic stroke, which is caused by bleeding into the brain.
The study showed immediate, non-contrast MRI is about five times more sensitive than, and twice as accurate as immediate, non-contrast CT for diagnosing ischemic stroke.
However, the two technologies were equally effective in detecting acute intracranial hemorrhage, the study showed.
"Our results show that MRI is twice as accurate in distinguishing stroke from non-stroke," said Steven Warach, director of the NINDS Stroke Diagnostics and Therapeutic Section and senior investigator of the study. "Based on these results, MRI should become the preferred imaging technique for diagnosing patients with acute stroke."
Non-contrast CT has been the standard in emergency stroke treatment, mainly to rule out hemorrhagic stroke, which cannot be treated with anti-clotting medications, the researchers noted.
CT uses X-rays that are passed through the body at different angles and processed by a computer as cross-sectional images, while MRI uses computer-generated radio waves and a powerful magnet to produce three-dimensional images of body structures and nerves.
The findings appear in the Jan. 27 edition of The Lancet.