Before the test

Preparation for a CT scan varies, depending on the purpose of the study and the area of the body under examination. Prior to your appointment, you will be given specific instructions, but the following guidelines generally apply with some exceptions.

• Tell the doctor or staff about all medications you currently take. Unless instructed otherwise, take all prescribed medications on the day of your exam. If you are an insulin-dependent diabetic, inform our staff in advance for instructions regarding food restrictions and how to take your insulin before and after the test.
• Inform the doctor or staff about allergies you have, especially if you've had an allergic reaction to contrast materials during previous imaging procedures.
• Depending on the type of exam, you may be restricted as to what you are able to eat or drink prior to your appointment. Drinking plenty of fluids, such as water, juices, clear soups, decaffeinated coffee and tea is generally encouraged.
• Your doctor may order a blood test to check your kidney function, in which case, a technologist will draw blood for this purpose (prior to CCTA scan).
• Some procedures may require you to change into a hospital gown. Otherwise, dress in comfortable clothing, preferably without metal zippers, grommets, buckles, etc. It is best not to wear jewelry or hairclips, as you will most likely be asked to remove them. If you wear dentures, you may have to remove them.
• For procedures requiring the use of contrast agents, you may be instructed to arrive extra early, allowing time for the administration of the contrast material and for it to take effect.

During the test

With some minor differences, depending on the area of study, the actual scanning process is generally the same. You will be brought to a special room with the CT scanner and asked to lie motionless on a narrow table. To keep any movement from blurring the CT image, straps, pillows or special "cradles" may be used to hold a body part steady. You may be asked to briefly hold your breath.

As the exam begins, the table will move through the circular structure that looks like a donut, called the gantry, which contains the x-ray source. The actual scanning takes only a few minutes, during which you may hear some clicking and other noises. A technologist, stationed in a separate room but able to see you, is present throughout the process and is able to communicate with you via intercom.

After the test

Once the test is completed, you are free to leave and carry on with your normal activities. If you were given a contrast agent prior to the exam, you may be instructed to wait awhile at the hospital for observation to ensure that you don't have a delayed reaction to the contrast. Someone will apply a bandage to the site of the intravenous injection, which you can remove after an hour or so. If the site becomes swollen, red or painful after 1-2 days, call your doctor. Unless told otherwise, drink plenty of fluids to help flush out the contrast materials from your body. This occurs naturally and takes about a day. Diabetics may be given additional instructions regarding food intake and insulin injections following the exam.