What is a CT Scan?
CT scanning uses X-ray beams to create cross-sectional images (slices) to produce 3-D pictures of internal organs. CT imagery is different than other imaging because it can display a combination of soft tissue, bones and blood vessels all in a single clear image.
There are a wide range of CT scanners available to patients, from 16-slice scanners for routine imaging, all the way to state-of-the-art 128-slice scanners for when ultra-high resolution and short imaging times are needed.
What to Expect During a CT Scan
The actual CT scanning takes less than 30 seconds and the entire process is usually completed within 30 minutes.
- You will be positioned on the CT examination table, usually lying flat on your back or less commonly, on your side or on your stomach. Straps and pillows may be used to help you maintain the correct position and to hold still during the exam. Depending on the part of the body being scanned, you may be asked to keep your hands over your head.
- If a contrast material is used, it will be injected into a vein shortly before scanning begins.
- The table will move through the machine as the actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes.
- You may be asked to hold your breath during the scanning.
Preparing for a CT Scan
- Wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure.
- Metal objects including jewelry, eyeglasses, dentures and hairpins should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work.
- You may be asked not to eat or drink anything for several hours beforehand, especially if a contrast material will be used in your exam.
- Please inform your physician of all medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or “dye,” your doctor may prescribe medications to reduce the risk of an allergic reaction.
- Inform your doctor of any recent illnesses or other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may increase the risk of an unusual adverse effect.
- Women should always inform their physician and the CT technologist if there is any possibility that they are pregnant.