Memory loss, personality changes, a shrinking ability to do daily tasks. It's not easy to watch a loved one suffer from dementia. It's also not easy at times for doctors to know exactly what kind of dementia a person may have. That's because there's not been a test that can differentiate between, say, Alzheimer's disease and Lewy Body Dementia. Now, researchers at Mayo Clinic have developed a way to look at the living brain and more accurately tell what type of dementia a person has. And this may help get patients on the right treatment.