Metallic stents: Evaluation of MR imaging safety

OBJECTIVE, The objective of our investigation was to evaluate safety during MR imaging (i.e., magnetic field interactions, heating, and artifacts) for metallic stents. MATERIALS AND METHODS. Different types of metallic stents were tested for m agnetic field interactions, heating, and artifacts using a 1.5-T MR system. Magnetic field-related translational attraction and torque were assessed u sing previously described techniques. Heating was evaluated using an infrar ed thermometer to record temperatures immediately before and after performi ng MR imaging using a whole-body-averaged specific absorption rate of 1.3 W /kg. Artifacts were assessed by placing the stents inside a fluid-filled ph antom and performing MR imaging using fast spoiled gradient-echo and T1-wei ghted spin-echo pulse sequences. RESULTS. For the 10 different stents evaluated, we found no magnetic field interactions, the highest temperature change was less than or equal to+0.3 degrees C, and the artifacts involved signal voids that would not create di agnostic problems as long as the area of interest was not positioned exactl y when a particular stent was located, CONCLUSION, The findings of the safety tests indicated that the 10 differen t metallic stents would be safe for patients undergoing MR imaging procedur es using MR systems with static magnetic fields of 1.5 T or less.