Magnetic resonance measures in Alzheimer disease: their utility in early diagnosis and evaluating disease progression.

We sought to identify the most reliable magnetic resonance (MR) measures for the diagnosis and staging of Alzheimer disease (AD) in a clinical setting and to estimate, for different degrees of dementia, the rate of change of cerebral atrophy in certain regions of interest (ROIs). Forty-two probable AD patients and eight normal controls underwent MR brain scans, neurological examinations, and neuropsychological testing. We computed each subject's corpus callosum width, ventricular size, right and left temporal lobe areas, interuncal distance, and assessed the degree of cortical atrophy. We also estimated the rate of change for Information-Memory-Concentration Test scores and for temporal lobe areas and corpus callosum width. Measures of temporal lobe area and subjective evaluation of temporal lobe atrophy both served to distinguish controls from mild AD cases (p < 0.05), whereas only the latter differentiated moderate from severe patients (p < 0.05). The rate of change for temporal lobe areas remained constant over different AD stages, whereas those for corpus callosum width and for cognitive impairment were greater for severe cases (p < 0.05). Our findings imply that measurements of temporal lobe area and ratings of temporoparietal atrophy can be useful in the diagnosis and staging of AD and suggest that atrophy progressed at different rates in selected ROIs for various stages of AD severity.