What is Computed Tomography?

Computed tomography, also called a CT or CAT scan, is a non-invasive test that uses X-rays and a computer to take detailed images of your child’s organs and bones.  

CT scans help doctors diagnose a wide range of conditions due to injury or illness, such as causes for abdominal pain, evaluating injuries due to trauma, and diagnosing cancer. CT scans can also check blood vessels throughout the body.

FUN FACT: Without the English rock band The Beatles, we wouldn’t have CT. Godfrey Hounsfield invented the CT scanner with funding from EMI (Electrical and Musical Industries). EMI was the record label that The Beatles were signed to, and the company used the profits from their success to fund Hounsfield’s research in CT.

How to Prepare for a CT Scan

You will receive specific instruction before your child’s appointment, but here are a few tips to help prepare for the exam and answers to some commonly asked questions:

  • Take time to talk to your child and explain the test. Reassure them they’ll be safe and comfortable. For preschoolers, it’s best to discuss the day of the scan; for school-aged children, it’s best to discuss two to three days before; and for adolescents, it's best to discuss one to two weeks before.
  • Ask your provider about letting your child play with our Kitten Scanner – a mini replica of a CT scanner.
  • Bring a comfort item, such as a stuffed animal, toy or blanket to use during waiting times or in the imaging room
  • Dress your child in comfortable clothing without zippers and snaps.

It depends:

  • Children getting non-contrast CT studies can eat and drink normally.
  • Children getting contrast CT studies should fast three hours prior to the CT.
  • Children getting anesthesia for their CT study will need to fast.

Fasting instructions and other information will be given when the scan is scheduled and by our nurses the day before the scan. If you have any questions, you can call the scheduling department at 602-933-1215.

If your child needs contrast, they will need to be fasting for at least three hours before the CT. Our radiology nurses will give them an IV. We will also draw some blood to check kidney function prior to giving your child the contrast. Please let our nurses know if your child has diabetes or any kidney issues, as well as any allergies they may have.

Yes, unless otherwise directed not to.

  • Look: The CT machine looks like a big donut (minus the sprinkles). It is tall and has a big hole in the middle with a table that moves in and out.   
  • Sound: The CT machine doesn’t make any loud noises. It sounds like a dishwasher, and it makes a doorbell sound when it’s ready to take pictures. Depending on the CT exam, the machine may talk to you. It may say things like, “Take a deep breath” or “Please don’t swallow."  
  • Feel: A CT exam shouldn’t feel like anything unless your child is getting a contrast study. If they are getting contrast in CT, the contrast dye will make them feel warm all over. People also describe a feeling like going to the bathroom or funny tastes in their mouths. Occasionally, the contrast can make people feel nauseated, but these sensations usually go away after 10 minutes.

What to Expect During the CT Scan

It’s totally natural for your child to be a little nervous, but knowing what to expect during the CT scan can help. Here’s what your child can expect during the exam:

  • After checking in at the front desk, a nurse or CT tech will bring you to the nurse’s station or the CT room.   
  • Your child will be asked to change into a gown. If contrast is needed, a nurse will place an IV before coming into the CT room.  
  • Once we are in the CT room, your child will lie on our CT bed. Depending on the exam, your child will go headfirst into the CT scanner, or feet first into the CT scanner.
  • Once on the table, the machine will do all the moving for us. The table moves up and down, and in and out of the scanner. We always take 1-2 “practice pictures” or scouts. The “practice pictures” help us tell the computer what part of the body we are taking a picture of.
  • Once we have done our “practice pictures," it’s time for the real pictures. If we are doing a contrast study, this is when we will give the contrast through the IV. If contrast isn’t needed, then the next picture is like the first, the table just moves in and out.
  • Sometimes, we ask children to hold their breath during the scan. This prevents breathing motion on our pictures. The breath hold is typically only for 4-5 seconds.

Most CT scans take less than 10 minutes to complete.

Why Choose Us?

Phoenix Children’s harnesses technology to provide exceptional patient care. In a partnership with Philips, our hospital has access to a Philips IQon Spectral CT scanner. In some cases, this scanner can be used to give the pediatric radiologist more information than we would receive with traditional CT scans.

Medical radiation can be a concern for some parents. Here at Phoenix Children’s, we maintain our medical radiation doses as low as reasonably achievable (ALARA). All our CT protocols have been made by our pediatric radiologists to minimize radiation doses to children while maintaining imaging quality. For more information about medical radiation and your child, please visit Image Gently, a worldwide initiative dedicated to pediatric imaging safety.

Patient Resources

These materials from our Child Life team can help guide your discussion with your child about their CT scan:

Computed Tomography (CT) Scan Tomografía axial computada CT Scan with Anesthesia Tomografía con anestesia