How to prepare for your CT

CT machine demonstration

The actual scan itself doesn’t take very long, but with the preparation for setting up the test, you can expect to be in the room for 15 to 30 minutes on average.

Imaging Center staff will probably ask you to arrive early so that you can change clothes,  an IV can be started if necessary, and even in some cases do blood work (if it is needed and there are not recent labs).

If you are getting IV contrast, you will be asked to refrain from eating or drinking anything for three or four hours before the scan.

Generally, you do not need to bring someone with you, but it depends on the type of exam that you are having.  The appointment scheduler will let you know.

You should wear comfortable, loose-fitting clothing for your CT exam. Metal objects can affect the image, so avoid clothing with zippers and snaps. You may also be asked to remove hairpins, jewelry, eyeglasses, hearing aids and any removable dental work, depending on the part of your body that is being scanned.

Women should always inform their doctor or X-ray technologist if there is any possibility that they are pregnant.

How does the procedure work?

In many ways, CT scanning works like other X-ray examinations. Very small, controlled amounts of X-ray radiation are passed through the body, and different tissues absorb the radiation at different rates. Each time the X-ray tube and detector make a 360 degree rotation and an x-ray passes through your body, the image of a thin section or slice is acquired.

You might think of it like looking into a loaf of bread by cutting it into thin slices. When the image slices are reassembled by computer, the result is a very detailed, multidimensional view of the body’s interior.

A relatively new technique, spiral (helical) CT has improved the sensitivity of CT for the detection of many diseases. With spiral CT, refinements in detector technology support faster, higher-quality image acquisition with less radiation exposure. It is typically eight to 10 times faster than conventional CT. Such speed is beneficial in all patients, but especially in elderly, pediatric or critically ill patients, who may have difficulty holding their breath for long periods.

How is the procedure performed?

The technologist begins by positioning you on the CT table. Your body may be supported by pillows to help you hold still and in the proper position during the procedure. As the study proceeds, the table will move slowly into the opening in the center of the CT scanner. Depending on the area of your body being examined, the increments of movement may be so small that they are almost undetectable, or large enough that you will feel the sensation of motion.

A CT examination often requires the use of different contrast materials to enhance the visibility of certain tissues or blood vessels. The contrast material may be injected directly into your blood stream, given orally, or administered by enema, depending on the type of examination. Before administering the contrast material, the radiologist or technologist will ask whether you have any allergies, especially to medications or iodine, and you will be alone in the room during the procedure; however, the technologist can see, hear and speak with you at all times. For pediatric patients, a parent may be allowed in the room with the child to alleviate fear, but will be required to wear a lead apron to prevent radiation exposure.

Who interprets the results and how do I get them?

After the study is complete and read by the radiologist, the report automatically goes into your medical record.

Consult with your doctor, because he or she may want to schedule a follow up visit to review the findings, even if they are normal.