A CT scanner uses computerized tomography, which is a technology that enhances x-ray imagery, to produce thee-dimensional visuals of the subject being scanned. It is also sometimes referred to as a CAT scan. The advantage of a CT scanner is that it allows the physician to create a cross section of internal organs and structures, allowing them to be viewed from multiple angles at once. For many diagnostic purposes this cross section gives a more accurate representation of what is going on in the body.
CT scanners are often used to help diagnose problems in the muscles or bones, determine the location of tumors or blood clots, pinpoint a point of infection, or diagnose internal injuries, including internal bleeding. CT scanners are also used to monitor certain health conditions, such as cancer and heart disease. A doctor may also use a CT scanner as a guide during surgery or radiation therapy.
Some people should not have a CT scan. Women who are pregnant will normally be instructed to use a different type of diagnostic test to reduce the fetus' exposure to radiation. Some CT scans require the use of a contrast media, or dye. Someone undergoing a scan with contrast media may experience an allergic reaction to the contrast. Preexisting allergies, asthma, diabetes, heart or kidney problems, and some thyroid illnesses may increase the likelihood of suffering from an allergic reaction to the contrast media.
People that do experience a reaction to the contrast media may develop several symptoms. A mild reaction may result in hives and itching. Some people may develop swelling in the throat, which can be life threatening. For people with kidney ailments, the process of passing the contrast media can be taxing on the kidneys.
The contrast media is a reflective dye that is injected into a vein. The media blocks x-rays, and shows up white on images. This makes blood vessels, bowels, or other organs more easily visible. If a contrast media is used, it may be necessary to fast for a few hours before the scan. Depending on what the scan is looking for, it may also be necessary to change one's diet, or take a laxative before the procedure.
The scan may take place in a hospital or an outpatient imaging facility. The procedure is relatively quick, with the scan taking only a few minutes. You will be asked to lie on a table, which will slide into the ct scanner imaging tube. In some cases, the technician may ask you to hold your breath to avoid blurring the pictures. Once the scan is complete, your physician will study the images, and discuss the results with you.