A probe for intracerebral aromatic amino‐acid decarboxylase activity: Distribution and kinetics of [18F]6‐fluoro‐L‐m‐tyrosine in the human brain

Positron tomography, using [18F]6-fluoro-L-dopa as a tracer, has been used for the study of Parkinson's disease. Unfortunately, the analysis of data obtained with this agent is bedeviled because it readily forms labeled methylated metabolites that enter the brain. We have evaluated [18F]6-fluoro-L-m-tyrosine (FmT) as an alternative tracer to study intracerebral dopamine metabolism with positron tomography. Imaging studies in humans showed …