Using MRI to predict Alzheimer's disease

SAN DIEGO, April 6 (UPI) -- U.S. researchers say they may be able to use magnetic resonance imaging to predict which adults with mild cognitive impairment may progress to Alzheimer's.

Lead author Linda K. McEvoy of the University of California, San Diego School of Medicine, says mild cognitive impairment is an intermediate stage between the decline in mental abilities that occurs in normal aging and the more pronounced deterioration associated with dementia, which includes Alzheimer's disease.

People with mild cognitive impairment develop Alzheimer's disease at a rate of 15 percent to 20 percent per year -- significantly higher than the 1 percent to 2 percent rate for the general population. Some with mild cognitive impairment remain stable, others gradually decline and some quickly deteriorate.

A baseline MRI exam was conducted and a second MRI was performed a year later on 203 healthy adults, 317 patients with mild cognitive impairment and 164 patients with late-onset Alzheimer's disease.

The researchers used the MRI to measure the thickness of the cerebral cortex -- key to memory, attention, thought and language.

"MRI is very sensitive to brain atrophy," McEvoy says in a statement. "There's a pattern of cortical thinning associated with Alzheimer's disease that indicates the patient is more likely to progress to AD."

Using the MRI baseline data, the researchers calculated that the patients with mild cognitive impairment had a one-year risk of conversion to Alzheimer's disease ranging from 3 percent to 40 percent.

The findings are published online ahead of print in the June issue of Radiology.