小野　敦    Department   Kawasaki University of Medical Welfare  ,    Position   Professor
Language	English
Title	Effect of electromagnetic wave suppression sheet in magnetic resonance imaging system on radio-frequency-induced heating of the metallic implant
Conference	The 46th Annual Meeting of the Japanese Society for Magnetic Resonance in Medicine
Conference Type	Nationwide Conferences
Presentation Type	Speech
Lecture Type	General
Publisher and common publisher	◎Atsushi Ono, Shinichi Arao, Satoru Takata, Akihiko Tabuchi, Norio Yoshizaki, Yuki Ando
Date	2018/09/08
Venue (city and name of the country)	Kanazawa City, Japan
Summary	Radio-frequency-(RF)-induced heating in magnetic resonance imaging (MRI) may pose risks to patients with metallic implants. Electromagnetic wave suppression sheet (EWS-sheet) is a promising tool to suppress RF-induced heating. To date, there is no data that conclusively proves that EWS-sheets prevent temperature increase in metallic implants. The purpose of this study was to assess the effect of EWS-sheets on attenuation of RF-induced heating of conductive implants in MRI and investigate appropriate methods of covering the implants with EWS-sheets that enable reduction of temperature increase. The effect of using the EWS-sheet to deter RF-induced heating depends on the covering method and placement. By ensuring adequate overlap in the parallel direction, full and half covering allowed the implant to resist heating within safety limits. It was noted that deficient overlapping in the parallel direction and a large vertical space between the sheet and implant caused higher temperature increase in the implant than in cases without use of the EWS-sheet, as a result of enhancement of RF power and incident RF pulses. EWS-sheets may be useful for protecting patients with conductive implants from the risks of RF-induced heating. Further investigations are needed to define the safety guidelines more precisely.