Assessment of MRI Safety Issues for Stainless Steel Sutures used for Microtia Reconstruction

Publication date: Available online 19 June 2018
Source:Journal of Plastic, Reconstructive & Aesthetic Surgery
Author(s): TL Kraai, RB Loch, FG Shellock
IntroductionPotential magnetic resonance imaging issues for stainless steel sutures used for microtia reconstruction could be clinically significant from safety and diagnostic yield considerations. Therefore, the purpose of this investigation was to assess magnetic resonance issues (magnetic field interactions, heating, and artifacts) for different types of stainless steel sutures used for microtia reconstruction.MethodsSmall gauge, commonly used stainless steel sutures from four different manufacturers (5/-0 Steelex, Aesculap/B. Braun Medical, Inc.; Nagata 38 Gauge Microtia Wire, Bear Medical Corporation; Auricular Reco Wire, Medicon Surgical Inc.; and 5-0 B&S 35 Surgical Steel Suture, Ethicon, Inc.) were tested using standardized, ex vivo techniques to assess magnetic field interactions, heating, and artifacts at 3 Tesla. Prior to testing, the stainless steel sutures were configured as they would be for cartilage reconstruction used to treat microtia.ResultsEach stainless steel suture exhibited minor magnetic field interactions at 3 Tesla (translational attraction, deflection angle <10 degrees and no torque). Heating associated with a whole body averaged SAR of 2.9 W/kg was not excessive (highest temperature changes, ≤1.8°C). Artifacts were relatively minor in relation to the size and shape of each stainless steel suture (artifact size in relation to the size and shape of each stainless steel suture extending ≤ 5 mm).ConclusionsThe stainless steel sutures that underwent testing do not present additional risks to patients in a 3 Tesla or less setting (i.e., magnetic resonance conditional). Artifacts for these sutures may only be an issue within close proximity to the reconstructed ear.