A computerized tomography scan (CT) — formally known as computerized axial tomography or (CAT) — is a type of radiographic imaging procedure that takes many pictures of a given area for optimal evaluation of body structures. The many images generated from a CT scan can be manipulated on the computer to create different axial views of the body. In other words, the body's interior can be viewed along different axes, or planes, for comparison. Side effects mayb be long-term or short-term, depending upon when they might arise. Long-term side effects of CT scans are mostly conjecture, while short-term side effects may include anxiety or untoward reactions to the contrast dyes sometimes used for optimal visualization.
All documented side effects of CT scans are considered short term. The vast majority are secondary to the administration of fluorescent, or contrast, dyes used to increase visibility of certain details in the CT image. Contrast dyes — usually made of iodine — can cause allergic reactions in some patients, particularly individuals with a preexisting allergy to seafood. Fluorescent dye allergies are apparent more quickly when the contrast material is administered intravenously (IV) than by mouth, as intravenous administration of the medication distributes the dye more quickly throughout the body. Allergic reactions to contrast dyes can include the development of hives, rashes, itching or wheezing.
Other reactions to the procedure might be broadly considered side effects of CT scans. A common reaction to IV administration of an iodine-based contrast dye is an abrupt systemic flushing that is also described as a feeling of heat spreading throughout the body. This is a known reaction to the dye and is not reported to cause permanent difficulties. Many patients — already anxious about possible health problems and the unfamiliar procedure — report claustrophobia while within the cylindrical CT scanner. These patients are often sedated with anti-anxiety medication prior to the procedure and may thus experience drowsiness and sedation as a side effect of CT scans.
A CT scan uses a slightly higher amount of radiation than a usual x-ray to obtain its multiple images and exposure to radiation has been identified as increasing an individual's chance of developing cancer. Thus, potential long-term side effects of CT scans may include greater chances of developing a malignancy. These risks are reportedly less dangerous than failing to diagnose or monitor a current medical condition in an adult.