About Computed Tomography (CT)
Computed Tomography (CT), also known as computerized tomography or computed axial tomography (CAT), is an advanced X-ray technology that produces a sequence of detailed cross-sectional images of the interior of the head, spine, chest, abdomen or other areas of the body. The complex images are produced by rotating a focused X-ray beam around the patient and taking these X-ray images from numerous angles, guided by a computer. CT examinations produce detailed organ studies by capturing multiple individual image “slices.”
What to expect
For your CT examination you will be asked to lie on a table that rides on a track through the doughnut-shaped scanner. As the procedure begins, you will hear humming, buzzing or clicking sounds from the CT machine. The table will move in short steps through the scanner as the CT tube rotates around you. At each step, the scanner completes a separate view. The information is processed by the computer and displayed as images on a video screen to the technologist.
You should remain as still as possible to produce the clearest images. Depending upon the procedure being performed, you may be asked to hold your breath for up to 30 seconds. Most exams require 15 to 45 minutes to complete.
A RAS radiologist will interpret your CT scan and report the results to your physician within five working days.
Patient preparation
Tell your physician and the technologist if you think you may possibly be pregnant. You may be asked to change into a gown. We will advise you about any dietary restrictions when scheduling your appointment. You may continue to take prescribed medications with small sips of water prior to your exam.
• CT Abdomen and/or Pelvis - No food for 2 hours prior to scan, medications and clear fluids allowed and strongly encouraged. Please pick up a prep kit from an RAS Imaging Center at least 24 hours before your exam. Follow the special instructions very closely.
• CT Chest - No food 2 hours prior to exam. Fluids are strongly encouraged.
• CT Angiogram of Coronary Arteries - Contact office for special instructions.
• All other CT exams - No restrictions.
Side effects and complications
If you are given contrast medium intravenously, you may notice a metallic taste in your mouth and a warm sensation throughout your body. These sensations are harmless and subside within a few moments. Oral contrast medium may cause slight changes in bowel movements, which soon return to normal.
Some patients may have an allergic reaction to the contrast medium, which is iodine-based. Patients who are allergic to iodine may experience itching, sneezing or other allergic symptoms in response. If you are allergic to iodine but must be given contrast medium to produce the proper test results, your physician may choose to pre-medicate you with steroids or other drugs. Anyone experiencing such a reaction will be treated before being released to go home. In rare cases, the contrast medium can trigger anaphylaxis, a life-threatening allergic reaction in which the tissues of the airway become swollen enough to restrict breathing. In such cases, emergency treatment is immediately given. Please let us know if you know or think you are allergic to iodine.
Patients who have diabetes or renal disease require special care because the kidneys are involved in filtering iodine from the bloodstream. These patients should consult with their physician about proper scheduling of the CT scan.
Follow-up care
The CT exam itself requires no follow-up care.
Patient Information for CT Brochure Side 1
Patient Information for CT Brochure Side 2