What is Cardiovascular Computed Tomography (CCT Scan)?
During a cardiovascular computed tomography scan (CCT scan), the x-ray beam moves in a circle around the body. This allows for many different views of the same organ or structure, and provides much greater detail than conventional x-rays. The x-ray information is sent to a computer which interprets the x-ray data and displays it in 3-dimentional form on a monitor. While many images are taken during a CT scan, less radiation is received than during standard x-ray procedures. Cardiovascular CT is able to image the coronary arteries, aorta, great vessels and pulmonary vessels as well as the carotid arteries, renal arteries and lower extremity arteries in the legs.
Preparation:
Cardiovascular CT Angiography scans are done with contrast. “Contrast” refers to a substance injected into an intravenous line that causes the particular artery being studied to be seen more clearly. You will need to be NPO (fasting, or nothing by mouth) for four hours prior to the procedure. Your physician will provide specific instructions. Let your doctor know if you have a history of reduced or significantly compromised kidney function.
You will need to let your physician know if you have ever had a reaction to any contrast dye, or if you are allergic to iodine or shellfish. If you are pregnant or think you may be pregnant, you should notify your physician. It will be necessary for you to remain still and lie on your back for 10 to 15 minutes and be able to hold your breath for 15 seconds during the scan. The contrast is excreted from the body through your urine. It is recommended that you drink plenty of fluids after the test.
When You Arrive:
When you arrive, you will be asked to complete some paperwork. The CT staff will review these forms with you and ask some additional questions. You will also be asked to sign a consent form.
An IV placed in your arm for contrast medication.
If you are scheduled for a Cardiac CT Angiography, you will be connected to an EKG monitor to assess your heart rate. If your heart rate is too fast, a nurse will administer a medication known as a beta-blocker to bring your heart rate into an acceptable range. This may take 15 - 30 minutes. If your heart rate does not respond to the beta-blocker, it may be necessary to reschedule your exam for another day. At that time you will be prescribed an oral dose of beta-blocker. Once your heart rate is within the optimal range, you will be taken into the CT lab.
The Test:
The CT scanner is located in a large room. A narrow table slides into the hollow tube-shaped scanner. You will lie on the narrow table on your back with your arms above your head. You will be asked to take a deep breath and hold it. The longest you will have to hold your breath is approximately 20 seconds. You may want to practice this at home before your exam. This is VERY IMPORTANT as breathing motion can make the information obtained during the scan unusable.
When the IV contrast is administered, you will feel a warm sensation all over your body, and perhaps a metallic taste in your mouth. Some people even feel as though they have urinated. These are normal responses to the contrast that most people experience, and they subside very quickly.
After The Test: If beta-blockers were administered for your test, your heart rate and blood pressure will be monitored for about 20 minutes after the test. If not, you will be free to leave after your IV has been discontinued. You will be contacted by phone by your physician’s staff to discuss the results of your scan.
