DRD2 and multiple system atrophy: We report serial positron emission tomography images of both dopamine transporters and dopamine D2 receptors, obtained from a Japanese patient with Parkinson’s disease who underwent positron emission tomography scanning at ages 71, 72, 74, and 75 years, and another Japanese patient with multiple system atrophy who underwent positron emission tomography scanning at ages 65, 66, and 67 years.