MRI-magnetic resonance imaging - uses a combination of magnetism, radio waves and computer processing to create detailed images of nearly every body part and internal structure-from bones and joints to vital organs and tiny blood vessels in the brain.  Unlike imaging techniques based on X ray, with MRI there's no exposure to radiation. It is among the safest and most versatile of imaging methods. Since its introduction for medical purposes in the 1970s, advances in MRI technology have greatly improved image quality, speed and convenience for patients, while giving physicians a safe and versatile tool for screening, diagnosing, surgical planning, treatment and reconstruction.