What is computed tomography?
tomography, commonly known as a CT scan, uses X-rays and computers to
produce images of a cross-section of the body.
The patient must lie as still as possible as the table
moves through the large, donut-shaped scanning device. Movement could blur
the images produced by the scanner.
Before the test
Please be aware that
correct preparation is very important for the test to be performed properly.
- If intravenous contrast material is required for your CT scan, you might be
instructed to have a blood test before the CT scan appointment. The purpose
of the blood test is to assure your doctor that the appropriate contrast
agents will be used for an accurate diagnosis. Failure to obtain the blood test
might delay your CT scan appointment.
- 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 gelatin, tomato juice, and ginger ale.
On the day of the test
- Please plan to arrive 15 minutes before your scheduled appointment time.
This will help ensure that your CT scan can be completed on schedule.
- Take nothing by mouth for four hours immediately before your scan.
- If you are instructed to drink a special solution ("oral
preparation") to prepare for your scan, you will receive the solution
and instructions. Please follow the instructions carefully.
- Continue taking your medicines as usual. Consult your doctor if you
- You might be asked to change into a hospital gown because snaps and zippers
in street clothes can interfere with the scan. You also might be asked to
remove your watch or any jewelry.
- Please do not bring valuables such as jewelry or credit cards.
- Please allow one hour for your CT scan. Most scans take from 15 to 60
- The test is performed, and the results are reviewed by registered and
licensed technologists and board-certified radiologists.
During the test
- Depending on the type of scan you need, a contrast material might be
injected intravenously (into your vein) so the radiologist can see the body
structures on the CT image.
After the contrast agent is injected, you might feel flushed, or you might have a
metallic taste in your mouth. These are common reactions. If you experience
shortness of breath or any unusual symptoms, please tell the technologist.
- The technologist will help you lie in the correct position on the
examining table. The table will then automatically move into place for
imaging. It is very important that you lie as still as possible during the
entire procedure. Movement could blur the images. You might be asked to hold
your breath briefly at intervals when the X-ray images are taken.
After the test
Generally, you can
resume your usual activities and normal diet immediately.
The results of your CT scan should be available to your doctor within 24
hours after the test, Monday through Friday. Your doctor will discuss the
results with you.
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