Abstract
Magnetic resonance imaging (MRI) promises to become a valuable diagnostic tool for both diagnostic imaging and in vivo spectroscopy. MRI systems are already in place at a number of hospitals, and more units are expected to be installed when they receive FDA approval. Sonographers should understand the principles of MRI, since its use will interface with diagnostic medical ultrasound. A brief introduction to the physics of NMR is given. Typical MRI imaging equipment is described, including a comparison between superconducting, resistive, and permanent magnet systems. Some potential uses of this new technology are discussed. The safety and biologic effects of MRI are considered, and basic instructions for patient screening and preparation are given.