PET agent unlocks door to Alzheimer's disease

A PET agent built around fluorine-18 readily and safely distinguished the brains of Alzheimer's disease patients from those of healthy volunteers in a clinical trial at Johns Hopkins University.

Dr. Dean F. Wong, a professor of radiology and psychiatry at Johns Hopkins, and colleagues plugged F-18 into a compound known as florbetapir F-18, which is drawn to the beta-amyloid in Alzheimer's plaques. The compound has a half-life of about 110 minutes.

Testing the new compound in humans, Wong and his colleagues recruited 26 volunteers, 11 previously diagnosed with Alzheimer's disease and 15 healthy subjects of similar age who performed normally on cognitive tests. Each volunteer received a florbetapir PET scan, acquired over 90 minutes. The Alzheimer's patients showed significantly more of the agent in their brains than the healthy volunteers with the radiotracer accumulating in regions known to be associated with beta-amyloid deposits.