Health Library

CT (Computed Tomography) Scan

A CT scan can also be called a CAT scan. It uses X-rays to take pictures of the inside of a patient’s body.

The CT scanner is a large camera with a circle-shaped opening in the middle. Some people say it looks like a large doughnut. There is a table or bed that moves into the opening of the scanner during the scan and the patient may hear a humming noise similar to a washing machine. The scanner does not touch or hurt the patient.

It is important for the patient to hold still during the scan in order to obtain diagnostic images. Most CT scans are about 10 to 20 minutes in length. It may be necessary to schedule the appointment with anesthesia or sedation.

For some scans, the radiologist or the ordering doctor may require contrast.

The two most common types of contrast are given orally or by an IV. Depending on the details of the scan, both oral and IV contrast may be required.

Before the Scan

If the patient is scheduled with anesthesia or sedation, an anesthesia imaging nurse will contact you with preparation instructions. These must be followed carefully.

When You Arrive

Radiology staff will need to know the following:

• Patient allergies
• The last time the patient ate and drank
• If the patient has diabetes
• If the patient has had any other radiology procedures recently
• If the patient has any history of kidney or liver problems
• If there is a chance of pregnancy for anyone entering the scan room

After the Scan

The results are sent to the ordering doctor within 24-48 hours after the scan has been completed.