MRI Health Article

Why the test is performed

Combining MRIs with other imaging methods can often help the doctor make a more definitive diagnosis.

MRI images taken after a special dye (contrast) is delivered into the body may provide additional information about the blood vessels.

An MRA, or magnetic resonance angiogram, is a form of magnetic resonance imaging, which creates three-dimensional pictures of blood vessels. It is often used when traditional angiography cannot be done.

What the risks are

There is no ionizing radiation involved in MRI, and there have been no documented significant side effects of the magnetic fields and radio waves used on the human body to date.

The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions to the substance rarely occur. The person operating the machine will monitor your heart rate and breathing as needed.

MRI is usually not recommended for acute trauma situations, because traction and life-support equipment cannot safely enter the scanner area and the exam can take quite a bit of time.

People have been harmed in MRI machines when they did not remove metal objects from their clothes or when metal objects were left in the room by others.

For more information, see the specific MRI topics:

• Chest MRI
• Abdominal MRI
• Heart MRI
• Cranial MRI
• Lumbosacral spine MRI
• Spine MRI

References

Grainger RC, Allison D, Adam, Dixon AK. Diagnostic Radiology: A Textbook of Medical Imaging. 4th ed. Orlando, Fl: Churchill Livingstone; 2001:101-136.

Goldman L, Ausiello D. Cecil Textbook of Medicine, 22nd ed. Philadelphia, Pa: WB Saunders; 2004: 29.