Breast Tissue Expander With Radiofrequency Identification Port: Assessment of MRI Issues

Breast tissue expanders with magnetic ports are MRI unsafe, preventing patients from benefiting from the diagnostic capabilities of MRI. A tissue expander was recently developed with a radiofrequency identification (RFID) port used for needle location and expansion that may be acceptable for a patient undergoing MRI. The purpose of this investigation was to evaluate MRI issues using standardized techniques and well-accepted methods for this tissue expander with RFID port. The breast tissue expander with RFID port (Motiva Flora Tissue Expander, Establishment Labs) was assessed for magnetic field interactions (translational attraction and torque, 3 T), MRI-related heating (1.5 T/64 MHz and 3 T/128 MHz), artifacts (3 T), and functional changes associated with different MRI conditions (1.5 T/64 MHz and 3 T/128 MHz). Magnetic field interactions were minor (deflection angle of 2° and no torque) and thus will not pose a risk. At 1.5 T/64 MHz and 3 T/128 MHz, the highest temperature elevations (1.7°C and 1.9°C, respectively) were physiologically inconsequential. The tissue expander with RFID port exhibited relatively small artifacts on MRI. Exposures of the tissue expander with RFID port to different MRI conditions did not impact the ability to localize the RFID port or to read the electronic serial number. The findings indicated that this tissue expander with RFID port is "MR Conditional" for a patient referred for MRI at 1.5 T or 3 T. Importantly, the relatively small artifact associated with this implant offers potential advantages for patients undergoing MRI compared with tissue expanders that have magnetic ports that create substantial signal losses and distortions on MR images.