Computed Tomography (CT) Scans

UW Health radiologists use computed tomography (CT) scans to diagnose medical conditions inside of your body. A CT scan (also called a CAT scan) is short for computed tomography. A CT scanner takes a series of pictures inside your body while you rest on a scanning table, producing a series of detailed images, many of which would not show up on conventional X-rays. For some scans, an IV contrast will be injected into your vein to outline blood vessels or organs so that they can be seen more easily.
CT Scan Details
CT scans are common procedures, with University of Wisconsin Hospital and Clinics alone conducting more than 43,000 per year on average. The CT scanner is a large, donut-shaped chamber that houses an X-ray tube and a detector that sends information to a computer.
During the procedure, the patient lies on a couch which gradually slides through the CT scanner's chamber as the scanner takes the pictures using X-rays. The part of your body to be scanned is positioned in the middle of the scanner ring. You will be asked to keep as still as possible during the scan, and you may be asked to hold your breath (for 10-20 seconds) periodically throughout the scan.
Patient Concerns
Exposure to X-rays does pose a health risk, but doctors and other scientists believe that CT scans provide enough useful information to outweigh the associated risks. A CT scan is completely painless; however, if you receive IV contrast, you may feel a sensation of heat or discomfort during the injection.
Patients sometimes feel sick during the CT scan. The radiologist and technician can see patients through an observation window to monitor their condition, and the scanner has a two-way intercom so that patients can talk with the technologists. Someone is always available to help make the scan as comfortable as possible.