Amyloid Imaging

Amyloid-imaging agents such as 18F-florbetapir, 18F-flutemetamol, and 18F-florbetaben diffuse across the blood–brain barrier, are taken up in the neuritic plaques, and produce a radioactive signal that is detectable throughout the brain. The highest level of amyloid tracers uptake in the normal brain mostly regards white matter; in the body, they are enhanced in salivary glands, liver, muscles, and bone marrow. The uptake of amyloid tracers in the gray matter is linked to the deposition of amyloid. Therefore, these tracers are useful for PET and PET/CT imaging of amyloid-related kinds of dementia. In particular, PET with amyloid tracers is useful in evaluating patients with mild cognitive impairment and Alzheimer’s disease. Future studies are needed to clarify the potential added value of these radiopharmaceuticals in evaluation of systemic or cardiac amyloidosis. Diagnostic pitfalls can be due to rapid washout of tracers in the brain, faint uptake in vascular dementia, or motion artifacts in PET/CT fusion imaging.