Monoamine oxidase B inhibitor, selegiline, reduces 18F-THK5351 uptake in the human brain.

These results indicate that the interpretation of 18F-THK5351 PET images, with respect to tau, is confounded by the high MAO-B availability across the entire brain. In addition, the heterogeneous MAO-B availability across the cortex may limit the interpretation of 18F-THK5351 scans using reference region methods.