What is it?
CTA and MRA tests are non-invasive, advanced imaging studies that provide detailed information about the blood vessels within our bodies and their anatomic relationships with other organs. These tests use modern computerized image processing techniques that let your vascular surgeon view vascular disease three-dimensionally — an important step in assessing the extent of the disease and how best to treat it.
How are CTA and MRA tests similar?
Each requires an examination while you lie on a motorized bed that is wheeled into a gantry where scanner detectors are stationed in a circular fashion.
• Each may require administration of an intravenous (IV) contrasting agent that lets your vascular surgeon better visualize certain blood vessels.
How are they different?
There are more difference than similarities. Here are a few examples:
• All CTAs require the use of an IV contrast agent, but not all MRAs do.
• CTAs require exposure to radiation (see below), MRAs do not as they use magnets to create their images.
What to expect during the test?
Here is what MAY happen during the test:
• You will be placed on the exam table and positioned by a radiology technician.
• An IV line will be placed in your hand or arm.
• You may feel a warm sensation when the contrast material is injected, and you may notice a metallic taste for a brief period.
• The radiology technician will leave the room just before the exam table moves through the scanner. The technician will be able to observe you through a window from an adjacent room and talk with you though an intercom.
• Scanning is painless. You may hear clicking, whirring, and buzzing sounds as the scanner rotates around you.
• You may be asked to hold your breath during the scan.
• Depending on what body area is being scanned, the test may last for about 30 minutes up to an hour or so. You may have to wait a little longer until the technician doing the scan checks the images to make sure they are acceptable.
Are there any risks or side effects?
Which is right for you?
Your vascular surgeon decides which imaging study to perform based on a number of factors, including:
YOUR particular health issues that might include:
• Possible concerns with CTA: allergic reaction to the IV contrast agent, kidney disease or failure, pregnancy
• Possible concerns with MRA: presence of a pacemaker or AICD device, stimulators (e.g., for the spine), infusion pumps, certain implants. If Gadolinium IV contrast agent is ordered as part of the MRA: allergic reaction to the IV contrast agent, kidney disease or failure, pregnancy
• Which test/s are available in your community may be a factor. Not every medical institution offers both CTA and MRA tests as well as the expertise of medical specialists trained to interpret the images.
• Have a frank discussion with your vascular surgeon as to which test will be most helpful in diagnosing your vascular issue and developing a competent and safe treatment plan.
What about CTA radiation?
• While CTA is a safe test when performed judiciously, the amount of radiation involved is not insignificant if repeated examinations are planned.
• To get an idea of how much radiation is involved, the radiation from a typical CTA is equivalent to about 50 plain-film chest X-rays—about the amount of radiation the average person receives passively each year from the environment (“background radiation”).
• An MRA is considered preferable for repeated examinations, but the availability and expertise of interpreting MRA images varies as outlined above.
What should I do to prepare?
Preparation will vary depending on the particular test you are having done. Specific instructions will be discussed with you once the test has been chosen. It is VERY important that you follow the instructions exactly as you are told to avoid any unnecessary risk.
What can I expect after the test?
After the test is completed, you will have your IV removed. In most cases, you can return to all your normal activities at home. You may be given some additional instructions after the test, depending on your particular situation.
The information contained on www.ntxvascular.com is sourced from the Society for Vascular Surgery at www.vascular.org. It is purely informational, and is not intended, nor should it be relied upon, as a substitute for the advice or treatment of a trained medical professional. Individuals with specific medical problems or questions must consult with their doctor or other health care professional.