What to Expect During a CT Scan

The good news is that this imaging test is quick and simple

Doctor running CT scan from control room. Credit: Morsa Images / Getty Images

The medical term, Computed Tomography scan, is the long version for a CT scan, a special type of x-ray which is also sometimes referred to as a CAT scan.

The images produced by a CT scan are very detailed cross-sectional pictures of the body that allow for a look at tissues and organs inside the body. These images can help doctors diagnose conditions such as:

  • broken bones
  • tumors
  • blood clots
  • heart disease
  • head injury
  • to see whether cancer is responding to treatment
  • abdominal/pelvic pathology such as infectious complications/obstructions

What to Expect During a CT Scan

A CT scanner looks like a large, box-like machine with a short tunnel in the center. In addition, CT scanners typically have an examination table that slides in and out of the tunnel, while x-ray tubes and electronic x-ray detectors rotate around you.

A technician will be operating the CT scanner in an adjoining control room, with the ability to maintain visual contact through a window and hear or talk to you over a speaker and microphone. 

For a CT scan, you will lie on the examination table while it slowly moves through the center of the machine. While getting a CT scan is not painful, lying still on the table during the scan can be a bit uncomfortable. It is also important to remain still during the CT scan, as, any motion, whether breathing or body movements, can lead to a loss of image quality and blurring.

This is why the CT technician may ask you to hold your breath during certain parts of the scan.

The timing of the scan is variable but usually takes less than 30 minutes, depending on the type of CT scanner being used and the size of the area being scanned. The good news is that modern scanners can scan through large sections of the body in less than a few minutes and even faster in children.

This is helpful to all patients but especially for the critically ill, the elderly, and for children, since it can be difficult to remain still. In fact, many CT scanners are fast enough that children do not require sedation, but in special cases, sedation may be needed for those who cannot hold still.

Be aware that some CT scans may require the use of a contrast material to enhance visibility in the area of the body being examined. Contrast material may be swallowed, available through an intravenous line (IV) or, much less commonly, administered by enema, depending on the type of exam. 

There is a small amount of radiation exposure associated with CT scans. For children, the scanner is adjusted to their size so that the scan can be done with a reduced dose.

Once the examination is complete, you will have to wait until the technologist verifies the image quality of your scans for an accurate interpretation.

Finally, your CT image results are reviewed and analyzed by a trained radiologist who will send an official report to your doctor. Your doctor will then discuss your results with you.

How to Best Prepare for Your CT Scan

Even though you may be asked to change into a gown once you show up for your procedure, consider wearing comfortable and loose-fit clothing.

You will be given instructions on removing the following objects, as these may affect CT images:

  • Metal objects, including jewelry, eyeglasses, dentures, and hairpins
  • Hearing aids and removable dental work
  • Bras containing metal underwire
  • Remove any piercings, if possible

If contrast material is used during your procedure, you will be asked not to eat or drink anything for a few hours beforehand.

You will want to contact the doctor that referred you for the CT scan and let them know the following:

  • If you are on any medication
  • If you have any allergies to food coloring or dyes, as contrast material may contain such ingredients. Your doctor may prescribe medications (usually steroids) to reduce the risk of allergic reactions, which will need to be taken about 12 hours before contrast material. Contact your doctor well before the exact time of your CT scam to avoid any unnecessary delays.
  • Of any recent illnesses or medical conditions
  • Of any history of heart disease, asthma, diabetes, kidney disease or thyroid problems (these conditions may increase the risk of an unusual adverse effect).
  • Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant.

After this, try to relax during your CT scan, as it will likely be over before you know it. Thinking positive thoughts, counting sheep, or playing your favorite song in your head can help pass the time quickly. 

Sources:

National Cancer Institute. (2012). Radiation risks and pediatric computed tomography (CT): A guide for health care providers

Radiological Society of North America. (2016). Computed Tomography (CT) - Body. 

Continue Reading