CTA (computed tomography angiography) is an examination that uses x-rays to visualize blood flow in arterial vessels throughout the body, from arteries providing bloodflow the brain as well as those providing blood to the lungs, kidneys, and arms and legs. CT Angiography combines the use of x-rays with computerized analysis of the images. Beams of x-rays are passed from the gantry (a rotating device) through the area of interest in the patient's body from several different angles in order to gather isotropic data sets which then are assembled by computer into a three-dimensional picture of the area being studied. Those data sets can be used to reconstruct vessels, organs, etc. in order to provide all of the information the physician needs to accurately interpret your examination. Compared to catheter angiography, which involves placing a catheter and injecting contrast material into an artery, CTA is a much less invasive and more patient-friendly procedure. CTA injects contrast material into a peripheral vein rather than an artery.

If you are or suspect you might be pregnant, let your doctor, nurse or technologist know immediately.

What are some common uses of the procedure?

CTA is commonly used to:

CTA Chest

• Examine the pulmonary arteries in the lungs to rule out pulmonary embolism, a serious but treatable condition.

CTA Renal Arteries

• Visualize blood flow in the renal arteries (those supplying the kidneys) in patients with high blood pressure and those suspected of having kidney disorders. Narrowing (stenosis) of a renal artery is a cause of high blood pressure (hypertension) in some patients, and can be corrected. A special computerized method of viewing the images makes CT renal angiography a very accurate examination. Also done in prospective kidney donors.

CTA Chest, CTA Abdomen, CTA Pelvis

• Identify aneurysms in the aorta or in other major blood vessels. Aneurysms are diseased areas of a weakened blood vessel wall that bulges outólike a bulge in a tire. Aneurysms are life-threatening because they can rupture.
• Identify dissection in the aorta or its major branches. Dissection means that the layers of the artery wall peel away from each otherólike the layers of an onion. Dissection can cause pain and can be life-threatening.

CTA Brain

• Identify a small aneurysm or arterio-venous malformation inside the brain that can be life-threatening.

CTA Aorto-Iliac-Femoral

• Detect atherosclerotic disease that has narrowed the arteries to the legs.

CTA also is used to detect narrowing or obstruction of arteries in the pelvis and in the carotid arteries bringing blood from the heart to the brain. When a stent has been placed to restore blood flow in a diseased artery, CT angiography will show whether it is serving its purpose. Examining arteries in the brain may help reach a correct diagnosis in patients who complain of headaches, dizziness, ringing in the ears, or fainting. Injured patients may benefit from CTA if there is a possibility that one or more arteries have been damaged. In patients with a tumor it may be helpful for the surgeon to know the details of arteries feeding the growth.

Before the test

You will need to be NPO, meaning no foods or liquids, after midnight the night before your scheduled examination. For example, if you are scheduled on Monday, you will need to not eat or drink anything after midnight Sunday evening. If you are taking any diabetic medication, please check with your physician as to whether or not to take these medications the morning of the exam

During the Exam

If you are or suspect you might be pregnant, let your doctor, nurse or technologist know immediately. Before the test, please remove earrings, bobby pins, and hearing aids.

You will be asked to lie on the examining table, usually on your back. The movable table will be raised, lowered and moved in and out of the scanner opening. The area of your body being examined will remain inside the scanner. It is very important that you remain still when the images are being taken, so that the pictures are clear. An intercom will permit you to communicate with the technologist.

You will hear a variety of whirring, clicking, and other machine like noises during the examination. While your CT Scan is being checked for clarity, you may be asked to wait. If additional images are needed, they will be taken at that time.

After the Exam

Your CT will be reviewed by a board certified radiologist, who will pass the results on to your physician. Your doctor, in turn, will discuss the results with you. He/she may recommend further testing, or suggest a treatment plan for your condition. Make sure you have a clear understanding of your test results and their impact on your health. If you have questions, feel free to ask your doctor.

Most patients are able to return to normal diet and activities immediately following the exam.

If You Want More Information.

Please feel free to call the CRH Imaging department at 918-225-8220.