A chest CT scan takes about 30 minutes, which includes preparation time. The actual scanning time is much shorter, only a few minutes or less.
The CT scanner is a large, tunnel-like machine that has a hole in the middle. You'll lie on a narrow table that moves through the hole.
While you're inside the scanner, an x-ray tube moves around your body. You'll hear soft buzzing, clicking, or whirring noises as the scanner takes pictures.
The CT scan technician who controls the machine will be in the next room. He or she can see you through a glass window and talk to you through a speaker.
Moving your body can cause the pictures to blur. The technician will ask you to lie still and hold your breath for short periods. This will help make the pictures as clear as possible.
The scan itself doesn't hurt, but you may feel anxious if you get nervous in tight or closed spaces. Your doctor may give you medicine to help you relax.