What is CT?
Computed Tomography, otherwise known as "CT", is a specialized X-Ray imaging technique. CT creates images by using individual small X-Ray sensors and a computer. Data is collected by spinning the sensors around the patient. The computer then processes the information to create an image on the screen.
Depending on the circumstances, a contrast medium may be administered to aid in strengthening the resulting diagnosis. Most people tolerate the contrast medium without any problems and merely feel flushed for a moment.
Since the contrast medium contains iodine, which may cause an allergic reation in some people, you should consult your physician regarding any existing allergies, prior to your examination. Should you feel any discomfort during the examination, you can communicate this to the CT team at any time. Modern scanners are equipped with an intercom system for this purpose.
What Happens During an Exam?
During the examination, you will be lying on a comfortable patient table (usually on your back). This table will then slowly move you through the opening of the examination unit called the gantry. All you need to do is pay attention to the CT personnel who may, for example, ask you to briefly hold your breath or not ot move certain regions of your body.
As with conventional X-Ray examinations, you will not feel the acquisition of CT images at all; you will only hear a low whirling noise. The patient table will move slightly during the entire examination.
How long does it take?
There is no general answer to this question. The duration of a CT examination depends on the body regions being scanned. Although, with a modern spiral CT scanner, the actual images are produced within a few seconds.
You should expect the examination to last approximately 15 to 30 minutes. If a constrast medium is not used, the examination will take longer. You may also have to drink a contrast medium that will coat the gastrointestinal tract approximately one hour before the CT scan takes place.
The radiologist will analyze the images and send a report of the diagnosis to your referring physician, who will then discuss the results of the CT examination with you.
- If you have images from previous examinations (including X-Rays) please bring them with you.
- For head and neck examinations, please remove all jewelry, hairpins, eyeglasses, hearing aids, and dentures, or leave them at home.
- For abdominal examinations, plesae ask your physician how many hours prior to the exam you should refrain from eating or drinking.
- It is very important to let your physician know if you've had any previous allergic reactions to a contrast medium, iodine, or shellfish, or if you have asthma.
- If you have diabetes or take medications, please inform the technologist.