Computed Axial Tomography (CAT) scans are commonly used to provide a detailed view of internal portions of organs and separate overlaping structures. This technology that uses three-dimensional studies is used to diagnose a variety of problems.
What is a CAT scan?
Computed Axial Tomography uses a computer to combine X-rays taken at various angles around the body into an image showing a 2-dimensional cross-section of the body's tissues and organs. By combining several 2-dimensional "slices" obtained using this method, the computer can also assemble a 3-dimensional image of the body's interior. By varying the intensity of the X-ray beam, CAT technicians can better match the density of the tissue in question, allowing them to produce images suited for specific diagnoses. The result is a diagnostic procedure that reveals the internal structure of your body without the need for more invasive techniques, such as exploratory surgery.
Diagnosis
Because CAT scans allow a physician to clearly identify and distinguish different kinds of tissue, CAT is used to diagnose several types of cancer and to help plan cancer treatment procedures. CAT scans are also used to diagnose skeletal problems, and vascular disease, and identifying injuries to internal organs.
Your Exam
The CAT exam begins with the technologist positioning you on the CAT table, using pillows to help support and position the area of the body being scanned.
Depending on the area being examined, contrast dyes may be injected to obtain better image definition. A flushed feeling often accompanies dye injection, but the symptoms usually pass in a minute or two. Occasionally, patients are allergic to the dye, resulting in mild itching or hives. These are easily treated with medication. If you are allergic to iodine, a common contrast material, you should inform the technologist before the exam begins.
If the digestive system is being studied, instead of an intravenous injection, you may be asked to swallow contrast material or receive it as an enema. This may result in some mild discomfort, but the discomfort usually passes quickly.
During the procedure, you will be alone in the exam room, but you will have voice contact with the technologist at all times. The CT machine makes mild noise while it is in operation and you may feel the exam table moving you into or out of the machine's scanning area. The CT exam itself usually lasts from five to 30 minutes.
For more information about CAT scans, visit the American College of Radiology/Radiological Society of North America Web site.
