AAPM/RSNA physics tutorial for residents: MR artifacts, safety, and quality control.

Artifacts in magnetic resonance (MR) imaging result from the complex interaction of contemporary imager subsystems, including the main magnet, gradient coils, radiofrequency (RF) transmitter and receiver, and reconstruction algorithm used. An understanding of the sources of artifacts enables optimization of the MR imaging system performance. The increasing clinical use of very high magnetic field strengths, high-performance gradients, and multiple RF channels also mandates renewed attention to the biologic effects and physical safety of MR imaging. Radiologists should be aware of the potential physiologic effects of prolonged exposure to magnetic fields, acoustic noise, and RF energy during MR imaging and should use all the available methods for avoiding accidents and adverse effects. Imaging equipment should be regularly tested and monitored to ensure its stability and the uniformity of its functioning. Newly installed or upgraded MR systems should be tested by a physicist or qualified engineer before use. In addition, the authors recommend participation in the MR imaging accreditation program of the American College of Radiology to establish the initial framework for an adequate quality assurance program, which then can be further developed to fulfill local institutional needs. (c) RSNA, 2006.