OCTOBER 2013 • Vol. 2, Issue 4

61^st Home Study Addresses Metal in MRI

We We are pleased to present the SMRT Educational Seminars, Volume 16, Number 3: “MR Imaging Near Metal Implants.” This is the 61^st accredited home study developed by the SMRT, exclusively for SMRT members. The accreditation is conducted by the SMRT acting as a RCEEM (Recognized Continuing Education Evaluation Mechanism) for the ARRT. Category A credits are assigned to each home study, which can be used to maintain one’s ARRT advanced registry. SMRT Home Studies are also approved for AIR (Australian Institute of Radiography), NZIMRT (New Zealand Institute of Radiation Technology) and CPD Now (The College of Radiographers, United Kingdom) continuing professional development (CPD) activities.

Two peer-reviewed articles have been chosen for this home study issue. The authors of the first, "Magnetic Resonance Imaging Near Metal Implants" introduce their article by saying "The desire to apply magnetic resonance imaging (MRI) techniques in the vicinity of embedded metallic hardware is increasing." As the " . . . installation of prosthetic hardware can introduce a variety of orthopedic complications . . . this capability of MRI to identify soft tissue complications has the potential to both improve the accuracy of revision preparations and reduce the severity of treatment procedures." However, the challenges surrounding imaging near metal are well known to the MRI community.

In the second article, "New MR Imaging Methods for Metallic Implants in the Knee: Artifact Correction and Clinical Impact" the authors investigate the potential improvements that may be provided using two relatively new acquisition schemes (SEMAC and MAVRIC). They state "MRI is the imaging modality of choice for musculoskeletal imaging because it has superior soft tissue contrast compared to CT." However, ". . .MR image quality suffers from artifacts including both signal loss and distortion that result from the metal perturbing the main magnetic field and inducing strong and spatially varying local gradients." The in-depth discussion of the characteristics of the effects metal has on the MR image in both articles provides highly specific details of the different types of artifacts and distortion resulting in a roadmap to possible software corrections.

A special thank you to Laurian Rohoman, ACR, R.T. (R)(MR), CTIC, FSMRT, from Montreal, Quebec, Canada for acting as the Expert Reviewer.

Thanks also to Heidi Berns, M.S., R.T. (R)(MR), FSMRT, Chair of the SMRT RCEEM Ad-hoc committee from Coralville, Iowa, USA and all those who participate on this committee by reviewing the home studies for accreditation. Finally, many thanks to Jennifer Olson, Associate Executive Director, Mary Keydash, Publications Director, Linda O-Brown, SMRT Coordinator, Sally Moran, Director of Electronic Communications and the entire staff in the Berkeley, California, USA office of the ISMRM and SMRT for their insight and long hours spent supporting these educational symposia.