Computed Tomography

What is a CT or CAT scan?

A CT or CAT scan is a diagnostic imaging procedure that utilizes x-ray and computer technology to generate cross-sectional images, often called “slices”. A CT scan is capable of showing detailed horizontal and vertical images of any part of the body, including bones, fat, muscles and organs. CT scans may be performed to help diagnose tumors, investigate internal bleeding, or check for other internal injuries or damage. CT scans are more defined and precise than general x-rays and at the same time, minimize exposure to radiation.

In conventional x-rays, a beam of energy is directed at the body part being examined. A plate placed behind the part of the body to be x-rayed captures the variations of the energy beam after it has passed through the skin, bone, muscle and other tissue. While much information can be obtained from a standard x-ray, it is limited in the specific detail it can provide about internal organs and other structures within the body.

In computed Tomography, the x-ray beam moves in a circle around the body, allowing for many different views of the same organ or structure, providing much greater detail. The x-ray information is sent to a computer that interprets the data and displays it in 2-dimensional form on a monitor. While many images are taken during a CT scan, in most cases, the patient receives less radiation exposure than with a single standard x-ray.

Sometimes a CT scan will be taken with “contrast”. Contrast refers to a substance that is either taken by mouth or given through an intravenous line (IV). This contrast allows the particular organ or tissue under examination to be seen more clearly. Contrast examinations may require you to fast for a certain period of time before the procedure. Your physician will notify you of this prior to the procedure if necessary.

Reminders Before the Examination

Tell the radiologist:

• If you are allergic to iodine or other materials.
• If you are pregnant.
• If you are claustrophobic and think you will be unable to lie still while inside the scanning machine.