flortaucipir (18F)
Flortaucipir F-18, also known as 18F-T807 and 18F-AV-1451, is a small indole molecule synthesized with a radioactive fluorine isotope. It is used as a marker in positron emission tomography (PET) imaging of patients suspected of having Alzheimer's disease. After crossing the blood-brain barrier, flortaucipir F-18 binds to aggregated tau protein, a hallmark of Alzheimer's disease whose incidence correlates well with disease progression.  Although flortaucipir F-18 displays low levels of background binding throughout the brain, it does display off-target binding to monoamine oxidase MAO-A and MAO-B, as well as to regions containing high levels of melanin, neuromelanin, and iron.. It was approved by the FDA on May 28, 2020, for sale by Avid Radiopharmaceuticals under the name TAUVID™ and is the first FDA-approved molecule for imaging aggregated tau protein in the brain.