CT Scan

Video: How a CT scan works 

What is a CT scan?
A CT scan uses special X-ray equipment to produce cross-sectional images of the body. Unlike other imaging methods, CT scanning is able to show a very detailed view of several different types of tissue including soft tissue, lungs, fat, bone, and blood vessels.

The CT scanner is a large machine with a hole in the center, shaped something like a doughnut. Within the machine, an x-ray tube on a rotating gantry moves around the patient's body to produce images. As the study proceeds, the table slides slowly into the scanner. Depending on the area of the body being examined, the increments of movement might be either so small that they are almost undetectable, or large enough that the patient feels the sensation of motion.

How should I prepare for a CT scan?
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 might be asked to remove hairpins, jewelry, eyeglasses, hearing aids or any removable dental work that could obscure the images. You also might be asked to refrain from eating or drinking anything before your exam depending on the procedure. Women should always inform their doctor or technologist if there is any possibility of pregnancy. You can expect any CT procedure to take less than 30 minutes.

What will I experience during a CT scan?
The patient lies still on a table that can move up or down, and slide in and out from the center of the CT scanner. Pillows might be used to help hold you still, keep you in the proper position during the scan and to support you. You will be alone in the room during the scan; however, the technologist can see, hear and speak to you at all times.  For pediatric patients, a parent or guardian might be allowed in the room with the patient to alleviate fear, but will be required to wear a lead apron to prevent radiation exposure.

A CT examination of the abdomen or pelvis usually requires the use of an oral contrast material to visualize the gastrointestinal tract. This helps the radiologist differentiate tissues in the abdomen and pelvis. The contrast material is ingested a couple hours before you arrive for your procedure. You might also be asked to drink a small amount right before the test is started.

An injection of another type of contrast material might also be given through a vein in your arm. This contrast material also helps the radiologist visualize tissues and organs by "highlighting" them as it travels through your bloodstream. We ask that you do not eat starting four hours before this injection. In addition, if a patient is over 65 or is diabetic, we must obtain specific lab work before conducting this test.

If you have a question regarding a CT procedure you are having done, please contact us.

Last updated January 20, 2012