Brain scans may help early detection of Alzheimer's

A new research suggests that magnetic resonance imaging (MRI) could help detect Alzheimer's disease (AD) at an early stage, before irreversible damage has occurred. With no known treatment to alter its course, AD exacts an enormous toll on society. The Alzheimer's Association estimates that 5.4 million Americans are living with the disease today. "One of the things that made our study novel was that we looked at patients who were cognitively normal at baseline, rather than people with mild cognitive impairment," said lead author Gloria C Chiang.For the study, researchers looked at whether automated brain volume measurements on MRI could accurately predict future memory decline in elderly people with normal cognitive ability. They assessed 149 participants with an initial baseline MRI scan and a neuropsychological assessment. Follow-up exams two years later showed that 25 of the 149 initially cognitively normal participants, or 17%, had memory decline. Researchers looked at volume changes across a number of regions in the temporal and parietal lobes. The parietal lobe is primarily associated with the processing of sensory information and is involved in a number of cognitive and language processes. The predictive accuracy of the classification model increased as the number of brain regions included in the model increased. Models that took into account several areas of both the temporal and parietal lobes had an 81 percent accuracy rate in discriminating between cognitively normal people with and without memory decline. The findings illuminated how the interaction between these brain regions may play a key role in memory loss.  The study represents another step in the process of incorporating imaging into the diagnosis and management of Alzheimer's disease, according to Chiang.The study has been published online and in the June print edition of Radiology.