Response to Standardized MR Terminology and Reporting of Implants and Devices as Recommended by the American College of Radiology Subcommittee on MR Safety.

The U.S. Food and Drug Administration (FDA) continually works toward the goal of safety. For patients with magnetic resonance (MR) Conditional devices, safety is achieved when MR Conditional labeling is clear and accessible and can be unambiguously interpreted and applied. The FDA supports the three facets of standardization listed by the American College of Radiology (ACR) Subcommittee on MR Safety in their special report: (a) standardization in terminology and reporting of spatial gradient magnetic fields associated with MR systems; (b) standardization in reporting of ferromagnetic testing results for implants and devices; and (c) standardization, consistency, and clarity in radiofrequency power deposition guidelines and terminology. While the FDA is in agreement with the ACR Subcommittee on MR Safety that patient safety is of primary concern, the authors disagree with the Subcommittee on several important points and offer a point-by-point response to the Subcommittee's four recommendations. (©) RSNA, 2015.

In vitro tests reveal sample radiofrequency identification readers inducing clinically significant electromagnetic interference to implantable pacemakers and implantable cardioverter-defibrillators.

BACKGROUND: The use of radiofrequency identification (RFID) systems is expanding and highlights the need to address electromagnetic interference (EMI) to implantable pacemakers and implantable cardioverter-defibrillators (ICDs). OBJECTIVE: This study sought to examine the electromagnetic compatibility (EMC) between RFID readers and implantable pacemakers or ICDs. METHODS: During in vitro testing, 15 implantable pacemakers and 15 ICDs were exposed to 13 passive RFID readers in 3 frequency bands: 134 kHz (low frequency [LF]), 13.56 MHz (high frequency [HF]), and 915 MHz (ultra high frequency [UHF]). RESULTS: While being exposed to LF RFID, a reaction was observed for 67% of all pacemaker tests (maximum distance 60 cm) and 47% of all ICD tests (maximum distance 40 cm). During HF RFID exposure, a reaction was observed for 6% of all pacemaker tests (maximum distance 22.5 cm) and 1% of all ICD tests (maximum distance 7.5 cm). For both pacemakers and ICDs, no reactions were observed during exposure to UHF RFID or continuous-wave RFID. Pacemakers and ICDs were most susceptible to modulated LF RFID readers. CONCLUSION: Although there is in vitro testing evidence for concern for implantable pacemaker and ICD EMI at LF and HF, the FDA has not received any incident reports of pacemaker or ICD EMI caused by any RFID system. We do not believe the current situation reveals an urgent public health risk.