PET CT scanner is a large machine with a round, donut-shaped hole in the middle. You will lie on a narrow table that slides in and out of this hole. PET CT machine looks like a CT or MRI unit. The computer workstation that processes the imaging information is in a separate control room. This is where the technologist operates the scanner and monitors your exam in direct visual contact. The technologist will be able to hear and talk to you using a speaker and microphone.