After you arrive for your appointment, you will be escorted to a procedure room, where you will be asked to change into a patient gown. You should remove all jewelry and other removable items such as glasses, dentures, and hearing aids. Women should always inform their technologist if there is any possibility of pregnancy.
A nurse will first insert an intravenous (IV) line into a vein in your arm in order to administer an iodine-based contrast agent. Radiology Ltd. uses only non-ionic contrast agents (the safest kind), but with all contrast agents there is always the potential for allergic reaction. Be sure to tell your technologist if you have experienced a reaction to CT contrast in the past. You may also be given a beta-blocker medication through the same IV line or orally to help slow your heart rate in order to improve image quality. Nitroglycerin, which will dilate your coronary arteries for better visualization, may also be administered as a tablet or spray underneath your tongue.
During the exam you will lie on a table that moves into the doughnut-shaped scanner. Electrodes (small metal discs) will be attached to your chest and to an electrocardiograph (ECG) machine, which makes it possible to obtain the CT images when the heart is not actively contracting. You may be asked to raise your arms over your head for the duration of the exam to improve image quality, and you may also be asked to hold your breath during scanning. Your technologist will watch you through an observation window and will be able to communicate with you at all times. CT scans are non-invasive and painless, though you will hear humming, buzzing, or clicking sounds as the CT machine moves to position you. It is very important to follow all instructions and remain extremely still during scanning in order to obtain clear images. When the examination is completed, you will be asked to wait for the technologist to verify that the images are of high enough quality for accurate interpretation. The scan usually takes about 10-15 minutes if the heart rate is slow and steady, but please allow 2 1/2 hours for pre-procedure preparations and post-procedure observation.
The beta-blocker medication given to slow the heart rate can cause some patients to feel dizzy when they stand suddenly after the procedure due to a lowering of blood pressure. Because of this, you will be asked to sit up slowly on the table prior to standing. The dizziness is typically mild and occurs rarely. You may also have your blood pressure taken before, during, and following the examination if medications are given.
After the scan has been completed, you will be able to return to your normal activities and your usual diet unless otherwise instructed.
For your safety and the protection of others, we do not allow anyone other than patients in our exam rooms.