What is a CT or CAT Scan?

A Computerized Tomography/Computerized Axial Tomography (CT/CAT) scan combines data from a series of X-ray images to create detailed cross-sectional images of the body. A CT scanner emits a series of narrow beams through the human body which is caught by an X-ray detector to create a visual image of different levels of density. The computer stacks these images on top of each other to make a detailed image of your organs, bones, and blood vessels. 

Your doctor may recommend a CT scan to diagnose muscle and bone disorders, such as bone tumors and fractures; pinpoint the location of a tumor, infection, or blood clot, guide procedures such as surgery, biopsy, and radiation therapy, detect and monitor diseases, and conditions such as cancer heart disease lung nodules and liver masseuse; monitor the effectiveness of certain treatments, such as cancer treatment, detect internal injuries and internal bleeding. 

CT scans can help identify diseases or injuries within various regions of the body. For example, it can detect possible tumors or lesions in the abdomen and various types of heart disease. CT scans can also locate injuries, tumors, blood clots, and other conditions, such as complex bone fractures, bone tumors, and severely eroded joints. 

Your doctor may also recommend getting an abdominal CT scan if you have a mass in your abdomen that you can feel, abdominal pain, kidney stones, unexplained weight loss, infections, intestinal obstructions, inflammation of the intestines, trauma injuries, or a cancer diagnosis. 

Preparing for the Procedure

For the procedure, you will want to wear loose comfortable clothing. Ask ahead of time whether or not the imaging center has a hospital gown or clothing for you to use. If they do not, you will need to make sure that your clothing does not have any metal in it; meaning no zippers, buttons, belts, jewelry, eyeglasses, hair clips, dentures, hearing aids, bras with underwire nor piercings can be worn. 

Furthermore, your doctor may ask you to refrain from eating for 2-4 hours prior to the scan. You may also need to stop taking certain medications. Make sure to discuss your medications with your doctor and the imaging center. A radiology technologist will perform the CT scan. During the test, you’ll lie on a table inside a large doughnut-shaped CT machine. The table will move slowly into the scanner and then X-rays will rotate around your body. Throughout the scan, you’ll hear whirring and buzzing noises. You’ll have to remain still throughout the scan as any movement can blur the image making the image useless. The scan will take a few minutes to half an hour. 

The Scan

During the scan, only the patient will be left in the room. The technician will use pillows and straps to provide comfort and help you stay in the correct position. For example, for a head scan, a special cradle will be fitted to help hold your head still. 

Additionally, you will be able to communicate with your imaging technician through a 2-way intercom. At certain points, they may ask you to hold your breath and you can communicate with the technician if any issues occur.  

Preparing your child for a CT scan

If your child needs a CT scan, depending on age and demeanor your doctor may recommend a sedative for your child. If your child is getting a CT scan, you may be allowed to stand or sit nearby the scanning machine, however, you’ll need to wear a lead apron to prevent radiation exposure. 

Contrast Dye

For some CT scans, you may need to have a special dye called contrast material. Your radiologist may administer the contrast material orally, intravenously, or anally. Contrat material blocks X-rays and appears white in images which can help provide clarification for intestines, blood vessels, and other tissues. For example, an oral contrast material will help provide imaging for your esophagus and stomach. If the contract agents are injected, your urinary tract, liver, and blood vessels will be further defined in the scan. If your technician has to administer contrast material by enema, you may feel bloated and uncomfortable from the material. However, the CT scanner will provide precise images of your intestines. 

Potential Side Effects and Allergic Reactions

For contrast dyes, there is a risk of an allergic reaction. Most reactions to contrast dyes are mild and may result in rashes or itching. Barium (a type of contrast dye) can result in the following side effects: abdominal pain and cramps, diarrhea, nausea or vomiting, or constipation. If an iodine contrast is used, side effects may include skin rash or hives, itching,  and headaches. If you experience any of the following severe symptoms inform your doctor right away or go to the emergency room: trouble breathing, rapid heart rate, swelling of your throat, or any other tissue.

After a Procedure with Contrast Dye

If you need to have contrast material for your scan, you’ll receive special instructions. These instructions may include drinking lots of fluids to help your kidneys remove the contrast from your system. If you are breastfeeding, you’ll need to refrain from breastfeeding for 24 hours to ensure the contrast material doesn’t contaminate your breastmilk. 


CT scans use X-rays which produce ionizing radiation. Ionizing radiation may damage your DNA and lead to cancer; however, the chance of a CT scan causing cancer is 1 in 2,000. Nonetheless, your risk increases with every CT scan you get. 

Can I have a CT scan if I am Pregnant?

If you may be pregnant or may become pregnant inform your doctor right away as CT scans may expose your child to radiation. Your doctor can recommend alternative imaging. Normally CT scans are not recommended for pregnant women unless the benefits of the imaging outweigh the risk. 

I have Claustrophobia: Should I have a CT scan?

If you have claustrophobia inform your doctor and radiologist beforehand. They’ll provide a tablet or injection to help calm you down before the scan. 

Other things to let your doctor know prior to your scan

  • If you have any allergies to medication
  • If you are allergic to seafood or iodine
  • You are diabetic
  • You take metformin
    • If you are taking metformin, you may need to stop taking your medication for a period before and after the CT scan. 

Were you or someone you know involved in a recent auto accident? Call Auto Accident Care Network now at 801-683-1948 to be connected with a live care advocate. Our team at AACN can connect you to trusted attorneys and doctors to schedule a free legal consultation, a free thirty-minute massage, and a no-cost medical exam!  

Scroll to Top

If you’ve been in an auto accident in the last two months, please choose from the following:

Contact Us For