Computed tomography (CT) is an X-ray technique that produces more detailed images of your internal organs than a conventional X-ray can. The CT computer displays detailed picture images of organs, bones and other tissues. This procedure is also called CT scanning, computerized tomography, or computerized axial tomography (CAT).
What is it?
CT is a noninvasive way to view your internal organs and tissues.
CT is used to help:
Diagnose muscle and bone disorders, such as osteoporosis
Pinpoint the location of a tumor, infection or blood clot
Guide procedures such as surgery, biopsy and radiation therapy
Detect and monitor certain diseases such as cancer and heart disease
Detect internal injuries and internal bleeding
How do I prepare?
If intravenous contrast material is required for your CT scan, you may be instructed to have a blood test before your CT appointment. The blood test is to assure your physician that the appropriate contrast agents may be given for accurate diagnosis.
Drink only clear liquids after midnight the night before your scan. Clear liquids include clear broth, tea, strained fruit juices, strained vegetable soup, black coffee, plain Jell-O, tomato juice and ginger ale.
What to expect
Please plan to arrive 15 minutes before your scheduled appointment time. This will help ensure that your CT scan can be completed on schedule.
For four hours immediately before your scan, take nothing by mouth other than your regular medication(s). Consult your physician if you have questions.
If you are instructed to drink a special solution to prepare for your scan, you will receive the solution and instructions. Please follow the instructions carefully.
You may be asked to change into a hospital gown because snaps and zippers in street clothes can interfere with the scan. Please do not wear jewelry or a watch. They also will interfere with the scan.
Please do not bring valuables such as credit cards.
Please allow one hour for your CT scan. Most scans take from 15 to 60 minutes.
During the test
During the CT scan, you will be asked to lie very still on a table because movement can blur the images. You may be asked to hold your breath briefly at intervals as the images are taken. The table slowly passes through the center of a large X-ray machine. You may hear whirring and clicking sounds during the procedure. A technologist will be in a separate room supervising your exam and monitoring the images as they appear on the computer screen. The technologist can see and hear you, and you can communicate via intercom.
If a contrast material is injected intravenously (into your vein), you may feel flushed, or you may have a metallic taste in your mouth. These are common side effects. If you experience shortness of breath or any unusual symptoms, please tell the technologist.
After the test
Generally, you can resume your usual activities and normal diet immediately. If a contrast medium was used, your doctor or the radiography staff will give you any special instructions. These will likely include drinking lots of fluids to help pass the medium from your body.
CT images usually are printed from the computer onto film. A radiologist interprets these images and sends a report to your doctor. Your doctor will contact you to discuss the results.