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  • CAT Scan

    Computerized axial tomography (CAT) is an imaging test used to examine the body’s internal structures. During a CAT scan, a computer analyzes x-ray images taken from multiple angles. The result of this computerized analysis is a cross-sectional rendering of the human body.

    Computerized axial tomography is also known as computed tomography (CT scan) and computerized tomography.

    How can Computerized Axial Tomography Detect Cancer?

    Computerized axial tomography is used to diagnose and help treat cancer in a variety of ways:

    • Confirm tumor presence
    • Determine tumor shape, size, and location
    • Guide certain surgical procedures that do not allow a surgeon to directly see the inside of the body
    • Observe the progress of treatment
    • Help plan a treatment strategy and determine treatment options

    How is a CAT Scan Performed?

    The patient lies on a narrow table that slides into the CAT scanner. Patients may be asked lie on their back, side, or stomach, depending on the area of the body being studied.

    Inside the CAT scanner, an x-ray mechanism rotates around the patient. The patient must lie still during the test. Movement will result in blurry images. Patients may be asked to hold their breath for short periods of time. This reduces movement inside the body.

    Test Duration: 10 to 15 minutes. Recently developed multidetector scanners can render images of the entire body in less than 30 seconds. In the coming years, this technology will become commonplace in hospitals and imaging facilities throughout the U.S.

    Preparing for a CAT Scan

    Most patients are asked to avoid food prior to a CAT scan. This period of fasting seldom exceeds one day. To amplify the effects of fasting, a physician may ask the patient to take a laxative or enema before the test.

    Some CAT scan tests necessitate the use of contrast dies. Contrast dies illuminate certain structures within the body. They are injected directly into the patient’s bloodstream with a needle and syringe.

    You will be asked to remove all jewelry and/or metal accessories (i.e. belt buckles and glasses).

    CAT Scan Side Effects

    Computerized axial tomography is a noninvasive imaging test. As a result, it is not associated with the myriad of side effects common to surgical procedures and medications. Some CAT scan recipients, however, report feelings of mild to severe discomfort during the exam. This is especially the case with claustrophobic patients.

    When contrast dies are used, the patient may feel a mild burning sensation near the site of injection. Contrast dies can also cause a metallic taste in the mouth and hot flashes.

    All of the side effects associated with CAT scans typically subside within minutes.


    National Institute of Health Family of Sites. 2009. Retrieved on April 20, 2009 from.

    National Cancer Institute. 2009. Retrieved on April 20, 2009 from <>.

    University Hospitals of Cleveland Comprehensive Epilepsy Program Site. 2009. Retrieved on April 20, 2009 from.

    MedicineNet, Inc. 1996-2009. Retrieved on April 20, 2009 from.