Computed Tomography (CT) scanning, also called computerized axial tomography (CAT) scanning, is a medical imaging procedure that uses x-rays to show cross-sectional images of the body. A CT imaging system produces cross-sectional images or “slices” of areas of the body, like the slices in a loaf of bread. During a CT scan, a patient undergoes several consecutive and simultaneous X-rays that can be configured as a 3-dimensional reconstruction of the part of the body that is being imaged. Thus, a CT scan delivers more ionizing radiation to the patient than radiography. CTs are better able to distinguish between different types of tissues in the body than plain x-rays and, given its ability to image large areas over a short period of time, CT offers significantly improved resolution of many different structures in a variety of spatial configurations.
A CT scan will be performed using x-ray dye or contrast agent, which can be administered by mouth or by vein. This technique further helps to identify the organs and vasculature systemscan assist with the diagnosis of disease or injury.
How to Prepare
You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.
Metal objects, including jewelry, eyeglasses, dentures and hairpins, may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work. Women will be asked to remove bras containing metal underwire. You may be asked to remove any piercings, if possible.
You may be asked not to eat or drink anything for a few hours beforehand, as contrast material may be used in your exam. You should inform your physician of all medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or "dye," your doctor may prescribe medications (usually a steroid) to reduce the risk of an allergic reaction. To avoid unnecessary delays, contact your doctor before the exact time of your exam.