title: Radiofrequency heating studies on anesthetized swine using fractionated dipole antennas at 10.5 T.
abstract: OBJECTIVE
  To validate electromagnetic and thermal simulations with in vivo temperature measurements, and to demonstrate a framework that can be used to predict temperature increase caused by radiofrequency (RF) excitation with dipole transmitter arrays.
  
  
  METHODS
  Dipole arrays were used to deliver RF energy in the back/neck region of the swine using different RF excitation patterns (n = 2-4 per swine) for heating. The temperature in anesthetized swine (n = 3) was measured using fluoroscopic probes (n = 12) and compared against thermal modeling from animal-specific electromagnetic simulations.
  
  
  RESULTS
  Simulated temperature curves were in agreement with the measured data. The root mean square error between simulated and measured temperature rise at all locations (at the end of each RF excitation) is calculated as 0.37°C. The mean experimental temperature rise at the maximum temperature rise locations (averaged over all experiments) is calculated as 2.89°C. The root mean square error between simulated and measured temperature at the maximum temperature rise location is calculated as 0.57°C. (Error values are averaged over all experiments.) CONCLUSIONS: Electromagnetic and thermal simulations were validated with experiments. Thermal effects of RF excitation at 10.5 Tesla with dipoles were investigated. Magn Reson Med 79:479-488, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Yiğitcan
authors.initials: Y
authors.lastname: Eryaman
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Russell L
authors.initials: RL
authors.lastname: Lagore
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: M Arcan
authors.initials: MA
authors.lastname: Ertürk
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Utecht
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Torrado-Carvajal
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Esra Abaci
authors.initials: EA
authors.lastname: Türk
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Lance
authors.initials: L
authors.lastname: DelaBarre
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Metzger
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Gregor
authors.initials: G
authors.lastname: Adriany
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: Kâmil
authors.initials: K
authors.lastname: Uğurbil
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota, USA.
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Vaughan
mesh_terms: D000818:Animals; D002138:Calibration; D003198:Computer Simulation; D004574:Electromagnetic Fields; D060733:Electromagnetic Radiation; D004867:Equipment Design; D006358:Hot Temperature; D006979:Hyperthermia, Induced / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D011846:Radio Waves; D013552:Swine; D014057:Tomography, X-Ray Computed
keywords: 10.5 T; SAR; dipole arrays; radiofrequency (RF); temperature