A brain scan may predict alzheimer's disease. Should you get one?

Some experts fear PET scans offer few benefits, at substantial costs

Juli Engel was delighted when a neurologist recommended a PET scan to determine whether amyloid — the protein clumps associated with an increased risk of Alzheimer’s disease — was accumulating in her mother’s brain.
 
“My internal response was, ‘Yay!’” said Engel, 65, a geriatric care manager in Austin, Tex., who has been making almost monthly trips to help her mother in Florida. “He’s using every tool to try to determine what’s going on.”
 
Sue Engel, who’s 83 and lives in a retirement community in Leesburg, Fla., has been experiencing memory problems and other signs of cognitive decline for