PET scans of neurochemical activity could aid the differential diagnosis of dementia, according to University of Michigan researchers.

Dr. Kirk A. Frey and colleagues at the University's Movement Disorders Clinic enrolled 66 patients with mild cognitive impairment or mild dementia who underwent a standard neurological assessment and structural imaging of the brain. Based on test results, experts diagnosed these patients with Alzheimer's disease, frontotemporal dementia, or dementia with Lewy bodies.

Patients also underwent molecular imaging with carbon-11 Pittsburgh Compound B to measure amyloid plaque deposits and carbon-11 dihydrotetrabenazine PET to determine dopamine receptor integrity. The investigators found both PIB- and DTBZ-PET led to a revised, diagnosis in at least one of every four patients. Results were reported at the 2009 SNM meeting in Toronto.