Computed Tomography (CT Scan)

A CT (computed tomography) scan, sometimes called a CAT scan, uses special x-ray equipment to create images of your body. The x-ray machine rotates around your body and obtains cross-sectional images of different organs or body parts.

During the exam, the machine focuses a thin beam of x-ray on the part of your body that is being scanned. The beam moves very rapidly so that multiple images are created from various angles. The computer then analyzes these images and organizes them into a 3-D image.

Why Is a CT Exam Done?

A CT scan allows your doctor to obtain a detailed picture of the inside of your body without any surgical exploration. The images show all types of tissue, including bone, blood vessels, organs, and soft tissue like muscle. 

This kind of detailed, cross-sectional insight into your body helps your doctor diagnose medical conditions such as:

In addition, your doctor may use a CT scan to guide a biopsy or other minimally invasive procedure.

The CT scanner can also create images that help your doctor analyze blood flow to various organs, including the brain. For example, a stroke can be diagnosed at an early stage through this procedure.


It is important to note that while the CT scan itself is a painless exam, it does involve exposure to radiation. However, the benefits of an accurate and early diagnosis far outweigh the risk.

Before the Exam

The CT scan is a fast and patient-friendly exam. We ask that you wear comfortable, loose-fitting clothing, such as a sweatshirt without zippers or snaps. You may be asked to change into a gown depending on the area of your body to be scanned.

If a contrast agent will be used during your exam, you will receive instructions to fast for a few hours before your appointment, and you may need to arrive an hour or two prior to the imaging portion of the scan. If you are allergic to iodine contrast, please alert your technologist before the day of your appointment. 

Your doctor may also request a blood test prior to your scan.

If you have questions about a health condition that could affect your exam, or if you think you might be pregnant, please talk to a CT technologist or radiologist.

During the Exam

When you arrive on the day of your exam, you’ll check in and complete some paperwork. If necessary, you’ll change into a gown. You will also need to remove your jewelry and any other metal objects. 

You may be asked to drink an oral contrast agent one to two hours before the scan begins, or you may receive an injection of an intravenous contrast medium, or dye. The contrast medium helps to emphasize certain areas of the body over others so that your images are more accurate.

Please tell your CT technologist if you have any allergies to contrast medium or iodine, have been diagnosed with heart failure, diabetes, or kidney problems, or if you are claustrophobic.

In the scan room, you’ll see the CT scanner, which looks like a large donut. The technologist will help you lie on a special sliding table that will gently move you into position. Then the technologist will go inside a control room to monitor the scan in process. You can speak to the technologist at any time using a microphone built into the scanner.

The average scan takes between 10 and 20 minutes, depending on the location of the scan and the information needed. Once it begins, the table will move slowly as the x-ray tube rotates around your body. You will hear a soft clicking or whirring sound as the table moves. It is important that you lie still during the exam so the x-rays record an accurate image.

After the Exam

You may be asked to wait until the radiologist reviews your images to be sure additional images aren’t needed. 

If you ingested a contrast medium, it is important that you drink plenty of liquid over the 24-48 hours following your scan to help you pass the medium.

The radiologist will review your images and send a report to your doctor, who will notify you of any findings. You may also request to receive your images on CD. 

Request an Appointment

To speak with an Imaging Services representative or to schedule an appointment, please call 214-645-XRAY (9729).