CT is an abbreviation for computed tomography, which is a valuable diagnostic medical exam that combines X-rays and computers. Sometimes called CAT scans, CT scans have been performed successfully for over 30 years. It gives the Radiologist a non-invasive way to see inside your body.
One advantage of CT is its ability to rapidly acquire two-dimensional pictures of your anatomy. Using a computer, these 2-D images can be presented as 3-D images for in-depth clinical evaluations.
Why do people need a CT scan?
CT exams are performed when people are ill or injured, or when a doctor suspects a medical problem that cannot be detected easily with a routine physical examination. CT is also used to rapidly obtain specific diagnostic information that hasn’t been provided by other imaging technologies, such as ultrasound, traditional X-ray and magnetic resonance imaging (MRI).
What Should I expect?
A CT technologist will escort you into the CT scanning room, where you’ll see a table and a large, doughnut-shaped device called a gantry. You will be positioned comfortably on the padded table and asked to be as still as possible. You’ll also be asked to hold your breath for a short time to minimize any body movements and motion artifact.
How long will the exam take?
You will have to lie still only for a few seconds during the actual scan, in which the CT scanner acquires X-ray images of your body. The rest of the CT exam, however, takes longer while you wait for the images to be processed on the computer. The exam can take anywhere from 15 to 45 minutes depending on the type of exam. Most patients will be in and out of the room in under 20 minutes.
Are IVs or shots involved?
Depending on the exam, a solution called “contrast” might be administered through an IV to improve the accuracy of the examination. Because of this, it is very important to let your doctor know beforehand if you any allergies, especially an allergy to iodine-based products.
Safety of CT scans
Nearly 80 million CT exams are performed in the U.S. every year. The registered Radiologic Technologist (RT), who performs your CT scan must be certified by the American Registry of Radiology Technologists.
Preparing for a CT exam
Unless directed by your physician, the following guidelines will ensure your CT scan is performed under optimal conditions.
- Arrive dressed in comfortable clothing containing no metal.
- Visit the restroom shortly before the scan
- Take medications as usual, with minimal water. If you are taking pain medication, please do so 30 minutes before your scan to help you lie still.
- If you have had barium studies of your stomach or colon within the last 48 hours, please tell your physician beforehand or tell the CT technologist when you arrive.
For specific exams, follow these guidelines unless otherwise directed by your physician:
- Head Scan: Remove hairpins, earrings, etc. The scan will last less than 30 minutes.
- Abdomen and Pelvis Scan: You will usually be required to drink a water prep to outline the digestive system before the scan. This will be given to you by the CT technologist with instructions on how long to drink the prep. Do not eat or drink anything else (except taking medications) for four hours before your scan time. You will be asked to place your arms comfortably over your head and will be asked to hold your breath for about five seconds several times during the scan.
- Chest Scan: Do not eat or drink four hours before your scan time. Clothing containing metal should be removed. Women should remove their bra before the exam begins. You will be asked to place your arms comfortably over your head and will be asked to hold your breath for about five seconds several times during the scan.
- Spine Scan: It is not necessary to fast before your scan. You may be asked to place your arms comfortably over your head or your chest.
- Extremities: It is not necessary to fast before your scan. You may be asked to lie in an uncomfortable position for the extremity being scanned, but it will only be for a short period of time.