Magnetic resonance imaging of the musculoskeletal system. Part 1. Fundamental principles.

Magnetic resonance imaging has become a powerful tool for diagnosing many orthopaedic disorders. To use the technology appropriately and understand the nature of the images, it is important that the referring orthopaedic surgeon be familiar with the underlying principles of image formation. In this article, the author discusses the underlying physical phenomena, the instrumentation used for magnetic resonance imaging, and the principal determinants of the appearance of the image, in particular, the different pulse sequences. Paramagnetic contrast agents also are discussed briefly, and a few considerations regarding patient safety are addressed.