Brain imaging tests such as CT and MRI scans can be helpful biomarkers for frontotemporal dementia because of the typical atrophy of the frontal and temporal lobes sparing more posterior parts of the brain. For other types of dementia, these imaging tests are not as helpful, although they may be important to rule out tumors, strokes, and hydrocephalus (excess fluid in the brain). Over the last ten years or so, PET scans that can image beta-amyloid plaques and tau-containing tangles have been developed and are now clinically available. These scans can be very useful in confirming a diagnosis of Alzheimer’s and staging the severity of the disease in research settings. However, they are very expensive and often not covered by insurance, presenting barriers for clinical use outside of research.