CT Scan

A Radiology Procedure Used To Diagnose Problems In The HIV+ Person

A computerized axial tomography scan or a CT scan as it is more commonly referred to is a special x-ray technique that produces images of your internal organs that are more detailed than is possible with conventional x-rays. While both types of x-rays produce images using beams of radiation, the way they use those beams is what makes them different.

Conventional x-rays use a stationary machine to focus the beams on a specific area or body part. This produces a two-dimensional picture of that body part. The CT scan on the other hand uses a device that rotates around the body spreading the x-rays beams while it rotates. These images are then processed by a computer, resulting in crossectional images of the inside of the body.

Why Use CT Scanning?

CT scans are used in situations that require more detailed images than those created by conventional x-rays. For instance:

• To diagnose and locate tumors or masses in the body.
• To identify areas of infection or the presence of abscesses (pockets of infection).
• To guide procedures such as biopsies and radiation therapy.
• To monitor diseases such as cancer.

Opportunistic Infections Fact Sheets

Before A CT Scan

The preparation for your CT scan depends on what areas of the body are being scanned.

• Some CT scans require you to drink special solutions (contrast medium) that illuminate on a CT image.
• Some CT scans will require you to drink laxatives the night before your CT scan in order to clean out your bowels, making it possible to get a clearer image.
• CT scans that are being used to image your blood vessels or your brain will require an IV line to infuse a contrast solution that will illuminate the vessels on a CT image.
• Contrast media can also be given by enema in order to illuminate the lower GI tract.
• If you are having a CT that requires a contrast media, you may be asked not to eat or drink anything for a few hours before the test.

  Important Fact!
  On rare occasions, people can have an allergic reaction to the contrast solution. People with iodine or shellfish allergies are especially at risk. Notify your doctor if you have had a reaction to contrast media in the past or have an iodine or shellfish allergy.

During the CT Scan

You will be asked to wear a hospital gown and to remove any metal such as eye glasses, necklaces, and earrings. You will lie on a narrow table that moves through a large donut looking machine called a gantry. As you move slowly through the gantry, the x-ray tube moves around you within the gantry, shooting x-rays through your body. As the x-rays pass through your body, some are absorbed by body tissues. Detectors in the gantry measure the amount of radiation passing through your body without being absorbed by tissues. Computers convert these measurements into the images your doctor sees.

While the x-rays passing through you are painless, there may be some mild discomfort associated with the IV catheter if used during the test. You may also experience some cramping or a bad taste from the contrast solutions you drink or receive by enema.

Dealing With Diarrhea

After The CT Scan

After your CT scan, you can return to normal activity. If you receive intravenous contrast, drink plenty of water after the CT to help your kidneys flush the solution from your body. If you drank contrast media or received any by enema, your bowel movements may be a different color and consistency until the contrast media has left your intestinal track.

Important Note!
If you have any wheezing, hives, itching, or other signs and symptoms of a contrast allergy, call your doctor or go to the emergency department right away.