Computed Tomography Angiography

Computed tomography angiography (CTA) is a specialized x-ray scan that examines blood flow in arteries when they are filled with contrast dye (a substance that makes blood vessels show on an x-ray).  Computed tomography (CT) uses a sophisticated machine to take x-rays from many different views, producing detailed two dimensional (2-D) images that can be put together to form three dimensional (3-D) images.

Parts of the Body Involved

CTA can be used to view blood vessels throughout the body.  It is most commonly used to study the:

• Brain
• Neck
• Heart
• Lungs
• Kidneys
• Legs or arms

Reasons for Procedure

This procedure is done to help doctors identify diseased, narrowed, enlarged and blocked blood vessels and locate where internal bleeding may be occurring.  Some specific used include:

• Detect atherosclerosis (narrowing of the arteries) or an aneurysm (ballooning out of a section of a blood vessel), which could lead to a heart attack or stroke
• Examine arteries in the lungs to check for an embolism (blockage of a blood vessel by a blood clot or other foreign substance) 

Risk Factors for Complications During the Procedure

• Allergies, especially to x-ray dye, iodine, medications or certain foods including shellfish
• Underlying kidney problems or diabetes may predispose you to a higher risk of decreased kidney function from the x-ray dye
• Bleeding disorder 

What to Expect

Prior to the Procedure:

At your appointment before the test, your doctor will likely ask about:

• Your medical history
• Medications you take
• Allergies
• Whether you are pregnant or trying to get pregnant

In the days before your procedure:

Follow your doctor’s instructions regarding any changes in how you take your medications and any restrictions on your eating and drinking.

At the health care facility:

• A health care professional explains the procedure and answers any questions you may have
• You may be asked to remove any article of clothing if it interferes with the image.  Modesty will be preserved.
• You remove all jewelry, hair clips, dentures and other objects that could show on the x-rays and make them difficult to read
• You will be given a contrast dye.  Do not ear or drink anything for 4 hours before your exams.

Anesthesia

None

Description of the Procedure

Most of the time needed for this exam is spent setting up.  An intravenous line (IV) is placed in a vein, and you lie down on a narrow table, called a gantry.  Pillows may be used to keep you immobile in a certain position.  The part of your body that will be studied is moved inside the opening of the CT machine, and a test image is taken.  You are given a small amount of contrast material to check how long it takes to get to the area being studied.  Next, the IV is connected to an automatic injector and contrast material is injected.  After this, your scan begins.

You must stay very still during the scan.  The technologist may ask you to hold your breath for 10 to 25 seconds to ensure movement does not blur the images.  It only takes seconds to record all of the images needed.  Before the procedure and during the time that the imaging is not occurring, you can ask the technologist any questions and express any concerns you may have. 

After the Procedure

The images are checked, and, if needed, they are repeated. Since you have received contrast dye, drink extra fluids to flush it out of your body more quickly.

How long will it take?

You will spend about 10 to 15 minutes in the examination room.

Will it hurt?

The scan will not hurt, though you might feel restless from not moving.  You may feel warm and flushed when the contrast dye is injected.

Possible Complications

Complications are rare, but can include: 

• Allergic reaction to contrast dye
• Kidney damage from contrast dye is rare, but more common in diabetic patients with prior kidney problems and in patients with rare blood disorders.  Please make sure your technologist and doctor know of any problem you may have which is similar to these.

Average Hospital Stay

None 

Postoperative Care

None

Outcome

The radiologist (doctor who specializes in working with medical images) will examine the images and report the finding to your personal doctor, usually within 24 hours.  Your doctor will discuss the finding with you and any treatment needed.

Call Your Doctor If Any of the Following Occurs 

It is essential for you to monitor your recovery once you leave the health care facility.  In this way, you can alert your doctor to any problems right away.  Call your doctor immediately if any of the following occurs:

• Hives
• Itching
• Nausea
• Swollen or itchy eyes
• Tightness of the throat
• Trouble breathing