That was the finding of a Massachusetts General Hospital study presented May 7 at the American Roentgen Ray Society's annual meeting in San Diego.
The study found diffusion-weighted MRI was about 90 percent accurate in diagnosing stroke if the test was within six hours of the first symptoms. Accuracy was 89 percent at six to 12 hours and 90 percent at 12 to 24 hours.
The researchers say the results achieved with diffusion-weighted MRI are superior to previous studies with computed tomography (CT), which has an accuracy rate of 40 percent to 60 percent. CT of the brain is the method currently used most often to detect stroke.
Diffusion-weighted MRI is a fairly new technique. It creates images based on the diffusion properties of water in human cells. Diffusion-weighted MRI creates tqo images. In one image, a bright spot indicates evidence of stroke, while the same area shows up as a dark spot in the second image.
Here's where you can learn more about stroke.