Computed tomography (CT) scans assist doctors to find tumors, their shape, location, and size. They show a clear cross-section of the body, including soft tissues, blood vessels, organs, and bones. Doctors use CT scans to guide a needle when removing a small tissue during a biopsy and other types of treatments such as radiofrequency ablation.
CT scans use pencil-thin beams to create a series of images captured from different angles. The information is fed into the computer to create one picture that shows a particular area of the body. To get a clearer picture, special contrast materials are used during the scan. Patients can swallow the contrast materials orally or get injected through the vein.
During the scan:
- The patient will not eat or drink anything a few hours before taking the test.
- The doctor will ask the patient to undress and put on a hospital robe. Any metal objects like jewelry and piercing are not allowed when undergoing a CT scan. Therefore the patient will have to remove hair clips, hearing aids, dentures, and other metals to avoid affecting CT pictures. Inform the radiologist if you have any implanted medical device such as an infusion port or pacemaker.
- A CT scanner is doughnut shaped. The patient’s head will be held still in a special device and they will lie on a flat table that that slides back and forth inside a hole at the center of the scanner.
- When the table reaches into the opening, the x-ray tube will rotate within the scanner and send out tiny x-ray beams at precise angles. As the beams pass through the patient’s body, they are detected on the opposite side of the scanner.
- A buzzing and clicking sound will be heard as the scanner goes on and off. While scanning is taking place, the patient will be alone in the examination room, but the technologist will be on the other side of the room, communicating with the patient.
A CT scan is a painless procedure, but it can make the patient uncomfortable to keep still for minutes at certain positions. The process lasts for 10 to 30 minutes, depending on the part of the body being scanned. Complications and side effects of a CT scan are due to a reaction to the contrast dye. Such reactions include rashes, shortness of breath, itching, nausea, wheezing, and more.