Parkinson's disease: in vivo assessment of disease progression using positron emission tomography

Over the past two decades, positron emission tomography (PET) has provided valuable insights into the mechanisms of nigrostriatal degeneration in Parkinson's disease (PD). Furthermore, it allows the in vivo assessment of disease progression and the evaluation of treatment interventions. In this review, we shall discuss some of the issues and concerns that arise with the use of PET as a surrogate marker of disease progression in Parkinson's disease.