title: X-ray radiation causes electromagnetic interference in implantable cardiac pacemakers.
abstract: BACKGROUND
  X-rays are not thought to cause electromagnetic interference (EMI) in implantable cardiac pacemakers. However, x-ray radiation during computed tomography (CT) scanning has been reported to cause EMI in some implantable cardiac pacemakers. The objectives of this study were to identify the location within the pacemakers where x-ray radiation causes EMI and to investigate the association of EMI with the x-ray radiation conditions.
  
  
  METHODS
  We verified the location where x-ray radiation caused EMI using a CT scanner and conventional radiographic x-ray equipment. An inhibition test and an asynchronous test were performed using five types of implantable cardiac pacemakers.
  
  
  RESULTS
  X-ray radiation inhibited the pacing pulses of four types of implantable cardiac pacemakers when the body of each implantable cardiac pacemaker, containing a complementary metal-oxide semiconductor (CMOS), was scanned using a CT scanner. We confirmed that x-ray-induced EMI depends on the x-ray radiation conditions, that is, the tube voltage, tube current, x-ray dose, and direction of x-ray radiation, as well as the sensing thresholds of the implantable cardiac pacemakers.
  
  
  CONCLUSIONS
  X-ray radiation caused EMI in some implantable cardiac pacemakers, probably because the CMOS component was irradiated. The occurrence of EMI depended on the pacemaker model, sensing threshold of the pacemaker, and x-ray radiation conditions.
authors.affiliation: Department of Medical Engineering and Technology, School of Allied Health Sciences, Kitasato University, Kanagawa, Japan. hirose@kitasato-u.ac.jp
authors.forename: Minoru
authors.initials: M
authors.lastname: Hirose
authors.forename: Keiichi
authors.initials: K
authors.lastname: Tachikawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Ozaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Umezawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Shinbo
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kokubo
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Kobayashi
mesh_terms: D006801:Humans; D010138:Pacemaker, Artificial; D019736:Prostheses and Implants; D012666:Semiconductors; D015898:Tomography Scanners, X-Ray Computed / Q000009:adverse effects*; D014965:X-Rays / Q000009:adverse effects*