What is CT?

Computed Tomography, CT, is an x-ray examination using a scanner to produce a series of cross-sectional images of a selected part of the body. The CT examination involves the use of very small amounts of radiation. The images are made using a computer as well as x-rays. The examination is painless and is very helpful in evaluation of diseases of the bone, abdomen, and brain.

The CT scanner opening encircles your body during the exam ination. This opening contains an x-ray tube and receptors which are mounted opposite each other. These rotate around your body. With each rotation, or scan, a portion of the total image is accumulated by the receptor. The receptor then feeds the information into a computer. The computer calculates the density of each area within the body, based on the energy absorbed as the scanner rotates, and converts it into a picture of a section of your body. The calculations that are required by each scan take the computer only a few seconds to make, but would take a mathematician years of effort.

Procedure

For the examination, you may be asked to remove part or all of your clothing, and to wear a gown. After you enter the examination room, the technologist will position you on a special table. Blankets will be provided to keep you warm.

Once you are securely in place, you will be moved into the scanner opening. The technologist will control the scanner and monitor the progress of the examination from an adjacent room. You will be shown how to communicate with the technologist, if necessary.

As you are moved through the scanner opening, relax and remain as still as possible. You may be asked to hold your breath for a few seconds as each scan is made. You will hear a brief whirring sound as the x-ray equipment scans your body. After each image, or scan, is made, the table will move you into position for the next scan. Once the scan sequence has begun, it is important that you remain still until the technologist tells you the scan is over.

Post Exam

The intravenous contrast medium, if used, will be eliminated through your urine and should cause no discoloration. You should increase fluid intake after the scan to help your body eliminate the contrast. You can resume your regular diet immediately after the examination, unless told otherwise by your doctor.

The radiologist will review your examination before you leave to make sure adequate images have been obtained. He will then interpret the images and send a written report to your doctor. You doctor will discuss the results with you.