Magnetic resonance imaging (MRI) is a noninvasive medical test that helps physicians to diagnose and treat medical conditions. MRI uses a powerful magnetic field and radio frequency pulses connected with a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI does not use ionizing radiation (x-rays).Detailed MR images allow physicians to evaluate various parts of the body and determine the presence of certain diseases. The images can then be examined on a computer monitor, transmitted electronically, printed or copied to a CD.