How long does a PET scan take?

The PET scan procedure lasts about two hours, according to Mayo Clinic. Prior to the scan, the patient is given, orally or by injection, a radioactive drug that acts as a tracer. Absorption of this drug takes 30 to 60 minutes, and the actual scan lasts for about 30 minutes.

PET scans require hospital gowns, according to Mayo Clinic, so allow time to change before and after the procedure. In addition, schedule ample time to urinate before the scan. In cases where CT scans are also required, they are done first and add about 10 minutes to the total time of the procedure.