What is CT Angiography (CTA) ?

CT angiography (CTA) is a procedure used to visualize blood flow in arterial vessels throughout the body, from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs. It utilizes CT technology to detect, diagnose and aid in the treatment of heart disorders, stroke and blood vessel diseases. CTA combines the use of x-rays with a computer to create images. Compared to catheter angiography, which involves fluoroscopy, placing of a catheter and injecting contrast material into an artery, CTA is a much less invasive and more patient-friendly procedure.

Contrast material is injected into a peripheral vein rather than an artery. With Pacific Imaging's 64 slice scanner, CT angiography can easily be performed on an out-patient basis.

Common uses of CTA

● Evaluate the pulmonary arteries in the lungs for pulmonary embolism , a serious
   but treatable condition.
● Examine blood flow in the renal arteries (those supplying the kidneys) in patients with
   high blood pressure (hypertension) and those suspected of having kidney disorders.
   Narrowing or “stenosis” of a renal artery is a cause of high blood pressure in some
   patients, and can be corrected. CT renal angiography provides very accurate information
   for a proper diagnosis. This exam is also performed on prospective kidney donors.
● Identify aneurysms in the aorta or in other major blood vessels. Aneurysms are diseased
   areas of a weakened blood vessel wall that bulges out, similar to a bulge in a garden hose.
   Aneurysms are life-threatening because they can rupture.
● Visualize dissection in the aorta or its major branches. Dissection means that the layers of
   the artery wall peel away from each other, like the layers of an onion. Dissection can cause
   pain and can be life-threatening.
● Detect small aneurysms or arterio-venous malformations inside the brain that can be
   life-threatening.
● Evaluate atherosclerotic disease that has narrowed the arteries to the legs.

CTA also is used to identify narrowing or blockage in the carotid arteries which bring blood from the heart to the brain. In cases where a stent has been placed to restore blood flow in a diseased artery, CT angiography will show whether it patent and allowing proper blood flow. Examining arteries in the brain may help to define a proper diagnosis in patients who complain of headaches, dizziness, ringing in the ears, or fainting.


Trauma patients may benefit from CTA if there is suspicion that one or more arteries have been damaged. In patients with a tumor, it may be helpful for the surgeon to know which arteries are feeding the growth. Dedicated software programs are used to help identify and characterize tumors and blood vessels.

How does it work?

The CT scanner contains a large circular-shaped ring that your body quickly passes through on a moveable table. As you pass through the ring, the scanner takes a complete 360-degree picture of you that is sent to its computer. These pictures are then reconstructed to form a complete image of your internal anatomy. You will have contrast material injected into a vein in your arm. This will enable clear visualization of the blood vessels. An automated injecting device is used to control the timing and rate of injection, which continues during the time images are recorded. As many as one thousand of pictures may be recorded in a matter of seconds. The real work of CTA comes in post production, after the images are acquired. Powerful computer software programs process the images and make it possible to display them in different ways, for instance, in cross-sectional slices or as three-dimensional models of the blood vessels.

Patient Comfort

CTA takes about 5 to 10 minutes from the time the actual examination begins. Overall, you can expect to be in or near the examining room for 15 minutes. You may experience a sensation of warmth throughout your body as the contrast material is injected, but you should not feel pain at any time. All CT exams require that you remain still during the exam. Pillows and foam pads are used to help make it more comfortable. The examination table will move into and out of the scanner opening, but it is not enclosed and only a small part of your body will be inside at any one time. You may be asked to hold your breath for 10 to 20 seconds to ensure clear pictures.

Preparation

You will be asked to change into a comfortable robe for most procedures. Metal objects can affect the image, so avoid clothing with zippers and snaps. You may be asked to remove hairpins, jewelry, eyeglasses, hearing aids and any removable dental work that could obscure the images. You also may be asked to refrain from eating or drinking anything for 4 hours prior to the exam. Women should always inform their doctor or CT technologist if there is any possibility that they are pregnant.

After the test

Once the images have been recorded, you will be free to leave. You can eat immediately and it is a good idea to drink plenty of fluids in the hours after the exam to help flush contrast material out of your system. Patients are able to return to normal activities immediately following the scan.

Results

At Lifescape Imaging - Cypress, we have a radiologist / cardiologist on site for the exam to be interpreted promptly. All of our radiologists are Board Certified by the American College of Radiology. The results will be phoned, faxed, mailed, or delivered electronically to the referring physician. Your referring physician will share the results with you.