What Exactly is a CT Scan? 

Patient Undergoing For A Computerized Axial Tomography (CAT) Scan In Hospital



A computerized tomography (CT) or computerized axial tomography (CAT) scan is a painless, noninvasive diagnostic test that can show organs, bones, tissues, and even blood vessels. Rather than taking an image of one spot, like the traditional x-ray, a CT scan rotates around the patient taking a continuous picture that can be divided up into slices or made into a cross-sectional 3-D image. Because of the CT scan’s ability to show very small bones and the surrounding tissues, these tests are especially helpful in diagnosing spinal issues and injuries to the head and internal organs.

How Do I Prepare for a CT Scan?

This test is an outpatient procedure, and typically doesn’t require much preparation. It’s best to:

  • Wear comfortable clothes, although you may be required to wear a gown
  • Remove jewelry, eyeglasses, dentures, pins, and belts
  • For women, wear a bra without under wire
  • Check your instructions to see if your test requires you to fast (if your doctor selected a scan with contrast, you may be required to fast a few hours before your test)

What Can I Expect During the Test?

The machine itself is large with a tunnel through it. You’ll be asked to lay on a table that will move slowly through this tunnel. Only the part of your body that is being imaged will actually be in the machine, so most people don’t find the experience claustrophobic.

A technician will be watching you from another room, and have a microphone to communicate with you. If you do become distressed during the test, let the technician know.

You’ll need to be very still as the table moves through the machine. You may be asked to hold your breath at times to minimize movement. The machine may make some whirring and clicking noises as it’s working.

If your doctor ordered contrast, you will need to have iodine dye injected, or barium dye administered orally or through an enema.

The length of the test depends on what needs imaging. A small part of your body may take a few minutes, while a full body scan can take about 30 minutes.

When To Expect Results

After the test is done, it will be sent to a radiologist. The radiologist will examine the scan and write up a report to send to your doctor. Your doctor will call you with the results, typically two to three days after you’ve had the test.

What are the Risks Involved with CT Scans?

There are minimal risks involved with CT scans.

You may have an allergic reaction to the dye that’s used. This can cause mild itching or hives, or you may have trouble breathing if the allergy is severe. In very rare cases, the dye has caused kidney problems.

Women should let their doctor know if they are pregnant. The radiation can harm a fetus.

Radiation exposure is low, and is not considered to be a cause for concern. The extra risk of cancer from being exposed to this ionizing radiation is estimated at 1 in 2000, while the risk of cancer for a U.S. citizen in general is 1 in 5.

It’s important to remember the risk of not getting a correct diagnosis is much greater than the risk of the scan itself. CT scans save lives every day.

Our Doctors Are Here for You

If you have any questions or concerns about an upcoming procedure, please don’t hesitate to reach out. We strive to create a positive experience for you as we help you heal.