MR imaging charts volume changes in the medial temporal lobe that correlate with memory decline, according to researchers from New York University School of Medicine.
This is the first study to use MR to predict the conversion from normal thought process to a state referred to as mild cognitive impairment, according to the report published in the December issue of Radiology.
"This study uses a novel approach to examine longitudinal changes in the brain, which are less subject to bias than existing approaches and are highly reproducible," said coauthor Mony J. de Leon, Ed.D, director of the Center for Brain Health at NYU.
The researchers studied 45 healthy subjects older than 60 years of age. The subjects underwent MR exams and neurological tests at the beginning of the study and two or more follow-up exams over a six-year period.
The rate of brain atrophy between the baseline and the first follow-up exams was assessed by using an automated procedure that included spatial coregistration of the two images and regional brain boundary shift analysis.
Medial temporal lobe atrophy rate, through its interactions with sex and age, was the most significant predictor of decline, according to the study. Overall accuracy of prediction was 89% (in 40 of 45 subjects), with 91% specificity (29 of 32) and 85% sensitivity (11 of 13).
Early signs of memory loss are usually diagnosed as mild cognitive impairment. People with MCI decline to dementia at a rate of 10% to 15% annually, compared with 1% to 2% among healthy elderly individuals. Accurate and early recognition of changes in the atrophy rate could enable therapy and improve tracking of the progression of decline, the authors wrote.
