New imaging shows Alzheimer’s unfolding in live brains
The two major brain abnormalities that underlie Alzheimer’s disease can now be viewed simultaneously in brain scans while people are still alive, providing new insight into how the disease develops and whether drugs are working.
The breakthrough comes from the development of a harmless tracer chemical that is injected into the bloodstream and accumulates exclusively in “tau tangles” – one type of abnormality that occurs in the brains of people with Alzheimer’s and other kinds of dementia. Fluorescent light emitted from the chemical is picked up using positron emission tomography (PET), showing exactly where the tangles are. The tracer remains in the brain for a few hours before being broken down and expelled from the body.