What is MRI?

MRI or Magnetic Resonance Imaging, is used by physicians as a diagnostic tool to view parts of the body which cannot be imaged by X-ray or other types of diagnostic imaging. MR Imaging does not subject the patient nor the MR Tech to any radiation during a scan, because x-rays are not used. Because of the technology employed, MR scanning is considered to be extremely safe.

MRI units have a variety of components, including a powerful computer system that controls the magnets and electric frequencies used to create the images, the body of the machine itself and a sliding table on which the patient will be moved into position for imaging.

All MRI scanners use a superconducting magnet (containing many wire coils, which have extremely low resistance, through which electricity is passed) to create an electromagnetic field. Radiofrequency waves from another magnet, or coil, are sent into the patient’s body, allowing the water in the body tissue to be visualized and the resulting image to be captured. Because the body is almost entirely comprised of water, every part of the body can be seen by the MRI, but is it especially useful for imaging soft tissues which cannot be seen by x-ray. This electromagnetic field can be adjusted to different frequencies, depending upon the area of the body that is being scanned and the amount of contrast that is needed.

MRI is a very useful diagnostic tool, but it is very rarely the first step. The study is expensive, therefore most insurance plans require the patient to take many other steps first, such as a certain amount of time on anti-inflammatory medications, a steroid injection or physical therapy to see if the problem will resolve.

Return to MRI Frequently Asked Questions