A “CT” or “CAT” scan is the term used to describe a radiologic test known as “computed tomography” or “computed axial tomography”.  The CT scanner is a doughnut-shaped machine that takes pictures of cross sections of your body called “slices”.

CT can see inside the brain and other parts of the body, into areas that cannot be seen on regular x-ray examinations.  CT makes it possible to diagnose certain diseases earlier and more accurately than with other imaging tools.  Because most diseases are better treated when found early, CT scans can help save lives.

Is Is it uncomfortable? The test itself is completely painless.  You will be asked to lie quietly in the CT scanners “patient couch” during the study.  Depending on the type of study being done, you may be injected with contrasting agent in your arm during the scan, and/or asked to drink an oral contrasting agent before the scan.  The injection part of the procedure may be uncomfortable.  Some people say they get a “warm flash” during the injection, but this will pass in a few seconds after the contrast has been injected. Because contrast agents contain iodine, which may cause allergic reactions in some individuals, be sure to tell the technologist, nurse or radiologist if you had an allergic reaction to these agents before, or if you have other drug or environmental allergies.  You may have been given contrast material in the past as part of a CT scan, a kind of x-ray (also called an IVP), or a heart or blood vessel catheterization (also called an angiogram).  If you have had these tests in the past, tell your technologist what tests you have had prior to your CT. CT scanners use x-rays.  For your safety, the amount of radiation is kept to an absolute minimum and our equipment is calibrated to minimize your exposure.  Because x-rays can harm a developing fetus, however, be sure to tell the technologist, nurse or radiologist if you are, or think you may be, pregnant before preparing for the CT exam.

What can I do to prepare? That day On the day of your CT scan, please do not eat or drink for three hours prior to your CT appointment.  You may, however, take medications that have been prescribed by your doctor with small amounts of water or recommended fluids. Restricting solid foods in order to avoid stomach distress is a common safety precaution before many medical procedures At the CT scan suite Plan to arrive at our imaging center at least 15 minutes before your scheduled appointment.  This will allow the necessary time to prepare your paperwork.  You will be asked to fill our questionnaire about your medical history, medications you are taking,  and any allergies. If you are having a CT scan of your abdomen or pelvis, you need to arrive 1 hour and 15 minutes before your appointment.  You will be asked to drink barium, a fluid that helps mark your intestinal tract so that the radiologist may interpret your scans properly.  In fact, depending on your medical problem and the type of study being requested, you may be asked to drink one bottle of barium sulfate at bedtime the night before the study.  It is necessary for you to wait one hour after drinking the barium before you can be examined because it takes that long for the oral contrast to travel through your digestive track to coat the intestines. The CT technologist will explain the test your are having, and answer your questions.  Depending on the part of the body being scanned, you may be asked to remove metal objects, such as jewelry, and change into a hospital gown.

What happens during the scan? The technologist will bring you into the CT scan room where you will lie down on the patient couch (usually on you back).  You should get comfortable because it is very important that you do not move during the test.  CT exams differ depending on the part of your body being studied.  The radiologist will plan an examination that is best suited for you. For example, if your abdomen is being studied, a series of pictures will be taken from your lower chest down to your pelvis.  During such a study, you will be asked to hold your breath so that the pictures will not be blurred.  The machine will make some noise, and the couch will move slightly as it takes pictures.  Also, you may receive verbal instructions from the technologist throughout the test.   As part of the test, before or during the study, you may be given an injection of a contrast agent, by a technologist or doctor. This allows the radiologist to obtain specific data relating to the injury or disease that your doctor has diagnosed.  This information is very important to the planning of any treatments your doctor will recommend, so your cooperation during the scan is very important. Should you have any discomfort during the test or after the injection, tell the technologist or nurse.  All of the CT personnel are trained and certified to assist  you.

About Contrast In some cases, the doctor may order a contrasting agent.  This is injected to a vein in your arm.  This injection will demonstrate various injuries or diseases whereas a standard CT scan may not.  Your doctor knows whether or not you need the contrasting agent.

How long does it take? Each examination is tailored to individual requirements, so don’t be alarmed if your exam is different from one that you have had before, or if some additional pictures are taken after the first series is completed.  From start to finish, the picture-taking part of the test usually lasts only 10 to 15 minutes.

What happens after the scan? Once the CT staff are sure enough information has been collected, you may leave and go about your normal activities without restriction.