[18F]F-DOPA Imaging in Patients with Autonomic Failure

Patients will receive a 3-D emission scan following a 6-8 mCi slow bolus injection of \[18F\]FDOPA over a 30 second period. Serial scans are started simultaneously with the bolus injection of radiotracer and are obtained for approximately 95 minutes.

30 minutes prior to the PET scan, patients will receive the 200mg oral dose of carbidopa to prevent peripheral \[18F\]FDOPA metabolism to increase signal-to-noise ratio of the imaging.

30 minutes prior to the PET scan, patients will receive the 400mg oral dose of entacapone to prevent peripheral \[18F\]FDOPA metabolism to increase signal-to-noise ratio of the imaging.