A CT (or computerized tomography) scan combines computerized technology with a focused X-ray beam that passes through the body at various angles, producing clear, cross-sectional images. It is safe, fast and painless, and produces precise and accurate images of the body. A CT scan is one of a physician’s most important tools for examining the bones and internal organs. CT scans are able to detect many conditions that conventional X-rays cannot. CT scans can often take the place of other more invasive diagnostic techniques, such as exploratory surgery, saving the patient discomfort, cost, and inconvenience. The scans are also useful for monitoring a patient’s progress during or after treatment. CT scanning is considered a critical component of any evaluation of brain injuries or function. CT scans of the head may also be used to detect or rule out tumors, blood clots, and other disorders. These scans can also be especially important in diagnosing enlarged lymph nodes, pancreatic disease, back problems, or lung cancer. CT (or computerized tomography) is also used to perform a virtual colonoscopy, a procedure that examines the colon using conventional CT techniques.
What can I expect during a CT/CAT scan?
The procedure is fast and painless. Patients will be asked to lie on a table that will move through the scanner opening, taking images of the body. Patients may be asked to remain very still and hold their breath while the actual images are being made. The whole procedure usually lasts 30 minutes, depending on the type of test being performed.
How do I prepare for the CT/CAT scan?
Doctors will provide detailed information on preparing for the scan. Patients may be told to avoid food or drink for around 4 hours before the test, especially if an intravenous contrast injection is to be used. An oral contrast medium is often given, as well as a contrast enema. These techniques are used to highlight certain structures, including the stomach and bowel, making the images more diagnostic. Some people are allergic to certain contrast media. Patients with allergies, particularly to iodine, should inform their doctor and the medical center staff ahead of time. Patients who are pregnant must alert their doctor, who will decide whether it is safe to have a CT scan. Patients should wear comfortable clothing, leave jewelry at home, and must remove hairpins, eyeglasses, and dentures when having a head scan.