What is MRI Angiography?

Magnetic resonance angiography (MRA) is a special MRI study used for the evaluation of blood vessels. It utilizes MRI technology to detect, diagnose and aid the treatment of heart disorders, stroke, and blood vessel diseases. MRA provides detailed images of blood vessels without the use of x-rays or contrast material, although in some cases a special form of contrast may be given to make the MRI images even more detailed.

Common uses of MRA

● Many patients with arterial disease are now treated in the radiology department rather than undergoing surgery in an operating room. MRA is a very useful way of finding problems with blood vessels and determining the best treatment.

● Carotid arteries in the neck conduct blood to the brain and are a common site of atherosclerosis (narrowing or blockage of an artery). This reduces blood flow to the brain which can lead to stroke. If an ultrasound study shows that disease is present, many surgeons will choose to do the necessary operation after confirmation by MRA, eliminating the need for traditional catheter angiography.

● MRA has found wide use in evaluating patients for diseased intracranial arteries (blood vessels of the brain), so that only those with positive findings will need to have a more invasive catheter study.

● MRA also is used to detect disease of the aorta and in vessels supplying blood to the kidneys, lungs and legs.

● Patients with a family history of arterial aneurysm (ballooning out of a segment of the vessel wall), can be screened by MRA to see if they have a similar disorder that has not yet produced symptoms. If an aneurysm is found, it may be eliminated surgically, possibly avoiding serious or fatal bleeding.

How does it work?

MRI is a unique imaging method because it does not rely on ionizing radiation. Instead, radio waves are directed at protons in the body, the nuclei of hydrogen atoms, in a strong magnetic field. The protons are first "excited" and then "relaxed," emitting radio signals. This data is then computer-processed to generate an image. In the body, protons are most abundant in the hydrogen atoms of water (the "H" of H2O) so that an MRI image shows differences in the water content and distribution in the various body tissues. Different types of tissue such as ligaments, tendons and cartilage can easily be distinguished. Typically an MRI exam consists of 2 to 6 imaging sequences, each lasting approximately 2 to 8 minutes. Each sequence has its own level of contrast and shows a cross section of the body in one of several planes (right to left, front to back, upper to lower).

Patient Comfort

The MRI system we use was designed with patient comfort in mind. It's a scanner with an open style magnet. This gives us the added ability to accommodate large and claustrophobic patients who cannot be scanned in traditional systems. During the exam, the patient may be injected with an image enhancement agent, which in some conditions, helps to provide additional information. Music is provided through headphones during the exam. Patients may choose from a selection of CD's or may bring their own to listen to. Our scanner also has interior lights and air conditioning. Most exams take between 15 and 30 minutes depending on the type of information needed.

Preparation

There is no special preparation for an MRA exam. Because the magnetic field will draw into itself any iron-containing object in the body, you will be given a questionnaire prior to your scan to ensure your safety. MRI exam is safe, simple, and painless. However, because certain metals interfere with the MRI machine and the images produced, some patients cannot be examined if they have any of the following:

● Heart pacemaker or pacing wires
● Brain aneurysm clips
● Spinal rods
● Intrauterine device
● Vascular access port
● Metal plate(s), pins, screws or staples
● Metal fragments in one or both eyes
● Inner ear implants
● An implanted spinal cord stimulator or brain stimulator

The radiologist and technologist should know about any such item and also whether you have ever had a bullet or bullet fragments in your body, if you ever worked with metals, or if you have had joint replacement surgery. If you are uncertain, an x-ray can be taken to safely detect any metal objects. The technologist should be informed if you have fillings in your teeth. These could possibly distort images taken of the facial region or brain. Likewise, braces may pose problems.

The patient should wear comfortable clothing such as sweats without metal snaps or zippers. Robes are provided if needed. Hairpins should not be worn. No jewelry or watches should be worn into the scan room. It is best to leave your jewelry at home. The radiologist and technologist leave the examining room during the actual imaging process, but the patient can communicate with them at any time using an intercom. If deemed safe, we permit a family member or friend to stay in the room, or a parent if a child is being examined.

You may eat normally before the exam. Medications may be taken as usual. Even with our short bore, wide open flared scanner, some patients may still feel uneasy about having an MRI. If you suffer from claustrophobia, a sedative may be necessary to help put you at ease, though probably less than one in every 100 patients will need this. Special accommodations must be made prior to the administration of sedation. If you require sedation, you must be accompanied by a family member or friend to drive you home after your exam.

After the test

Patients may leave immediately following the exam because the MRI has no side effects.

Results

At Lifescape Imaging - Cypress, we have a radiologist / cardiologist on site for the test 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. The referring physician will share the results with the patient.