New Brain Scan May Predict Alzheimer's
Study Shows Diffusion Tensor Imaging May Help Identify Early Alzheimer's Disease
Jan. 6, 2010 -- A new imaging technique that measures the random motion of water within the brain may prove useful for detecting early signs of Alzheimer's disease.
The technique, known as diffusion tensor imaging (DTI) or diffusion MRI, is used to assess changes in the white matter regions of the brain.
But it is increasingly clear that DTI can also be used to identify very small structural changes in the gray matter of the brain, which is critical for learning and memory, researcher Giovanni A. Carlesimo, MD, PhD, of Italy's Tor Vergata University tells WebMD.
In a study published in the Jan. 19 issue of Neurology, Carlesimo and colleagues found that DTI scanning predicted declines in memory performance with more accuracy than traditional MRI.
"This type of brain scan appears to be a better way to measure how healthy the brain is in people who are experiencing memory loss," Carlesimo says in a news release. "This might help doctors when trying to differentiate between normal aging and diseases like Alzheimer's."
MRI, DTI, and Alzheimer's
The researchers recruited 76 healthy people between the ages of 20 and 80 for their study.
They performed DTI scanning of the hippocampus, which is the region of the brain that controls memory. They also performed conventional MRI scanning to assess the overall volume of the hippocampus and the study participants completed a battery of tests designed to measure memory function.
The researchers found that DTI scanning was better able to predict memory performance than measurement of hippocampus volume, especially in study participants over the age of 50.
But Carlesimo says more study is needed to prove that DTI scanning actually predicts Alzheimer's disease in people who have not yet shown clear evidence of memory impairment.
"There is wide agreement among researchers and clinicians that in order to be effective, [drug] treatments should start as soon as possible in patients with Alzheimer's disease," he says. "This, in turn, makes it critical to identify people at high risk for the disease as early and as accurately as possible."