What is a CT Scan?
A CT scan, also called computed or computerized tomography, is a type of X-ray test used for diagnosis. CT scans combine X-ray imaging with computerized image processing to create detailed images, or “slices” of tissues and organs at different depths in the body.
How to Prepare
- Dress in comfortable clothes. Also, avoid clothes with metal objects such as zippers and snaps, because those could affect the quality of the image. Wear a bra without an underwire if possible. Female patients undergoing a heart test should not wear a dress.
- For scans of some body parts, you might have to remove items such as jewelry, eyeglasses, hair pins, dentures, or hearing aids.
- Please do not eat any food 4 hours prior to your exam, but make sure you are hydrated by drinking plenty of water before the exam (the day before and the day of), especially if it is a contrast exam.
- Your exam might require oral or injected contrast material to help make tissues more visible to the scanner. If so, let the technologist know before you are given the contrast dose if:
- You have a history of allergies such as allergic reactions to contrast agents. The technologist will ask if you have a contrast allergy, kidney or heart problems, or if you take medication for high blood pressure or diabetes.
- You have a history of kidney problems, heart conditions, thyroid conditions, diabetes, or asthma. Patients with those issues/conditions could be at higher risk of a negative reaction to contrast agents or problems with eliminating the contrast material from the body after the exam.
What to Expect
CT scans can take from 5-30 minutes. To perform your scan, the technologist will be in a control room next to the exam room, but you will be able to see and verbally communicate with the technologist during the scan.
For the scan, you will lie on a table that will move slowly into the CT scanner, which resembles a large doughnut. Most people are not claustrophobic in it.
The technologist helps get you into the proper position for the exam. To help you remain still, the technologist might use pillows or other positioning devices. Depending on the body area the equipment is scanning, you might not notice the table’s motion.
You might have to wait on the table after the scan while the technologist reviews the images.
Additional diagnostic purposes for a CT scan include:
- Screening for or diagnosing heart disease or lung cancer
- Cancer diagnosis, staging, treatment planning, and treatment monitoring
- Imaging blood vessels
- Diagnosing and analyzing complex bone fractures or abnormalities
- Follow-up to prior imaging or for pre-op
- Diagnosing a stroke or identifying the causes of the stroke
- Detecting tumors
- Finding areas of internal bleeding or organ damage in patients who have suffered trauma
