MRI, or Magnetic Resonance Imaging, is an imaging technique using a very powerful magnet and sophisticated detectors or 'scanners' to obtain very detailed images of any part of the body. There is no radiation or x-rays involved. The MRI can be non-contrast, contrast, or both. If both, the non-contrast proceedure is done first.
No matter what part of the body is being imaged, the contrast is injected intravenously. A nurse or specially trained technician will start an IV, usually in the arm, and then the liquid contrast material is injected, and the MRI performed.