Some worry about emotional impact of early detection.
More than 5 million Americans live with Alzheimer's disease.
There is no cure, but there is a new test that can tell you if you have it.
Alzheimer's ranks second only to cancer among diseases people fear, according to a recent Harvard study.
The new scans are opening up an entire moral debate: would you want to know if you had Alzheimer's?
Doctors at Las Vegas' Lou Ruvo Clinic says it's entirely up to the patient but believe better care can be given earlier when you know.