title: Noninvasive, in vivo determination of uterine fibroid thermal conductivity in MRI-guided high intensity focused ultrasound therapy.
abstract: OBJECTIVE
  To estimate the local thermal conductivity of uterine fibroid in vivo at a high temperature range (60-80°C) typically encountered in magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) surgery. The thermal conductivity of uterine fibroids in vivo is unknown and knowledge about tissue thermal conductivity may aid in effective delivery of thermal energy for ablation.
  
  
  METHODS
  All subjects (nine women) provided written informed consent to participate in this Institutional Review Board-approved study. A total of 10 fibroids were treated using MRgHIFU surgery with real-time temperature monitoring during both heating and cooling periods. The local thermal conductivity was determined by analyzing the spatiotemporal spread of temperature during the cooling period.
  
  
  RESULTS
  The thermal conductivity of MRgHIFU-treated uterine fibroids was 0.47 ± 0.07 W·m(-1) ·K(-1) (range: 0.25∼0.67 W·m(-1) ·K(-1) ) which is slightly lower than the reported value for skeletal muscle at temperatures of <40°C (0.52 to 0.62 W·m(-1) ·K(-1) ).
  
  
  CONCLUSIONS
  It is possible to estimate the thermal conductivity of uterine fibroids in vivo from the spatiotemporal spread of temperature around the HIFU focus during the cooling period.
authors.affiliation: Department of Diagnostic and Interventional Radiology, CHI St. Luke's Health, Houston, Texas, USA.|Department of Physics and Texas Center for Superconductivity at University of Houston, Houston, Texas, USA.
authors.forename: Jiming
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Diagnostic and Interventional Radiology, CHI St. Luke's Health, Houston, Texas, USA.
authors.forename: John
authors.initials: J
authors.lastname: Fischer
authors.affiliation: Philips Healthcare, USA.
authors.forename: Lizette
authors.initials: L
authors.lastname: Warner
authors.affiliation: University of Chicago Medical Center, Chicago, Illinois, USA.
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
authors.affiliation: Department of Physics and Texas Center for Superconductivity at University of Houston, Houston, Texas, USA.
authors.forename: Pei-Herng
authors.initials: PH
authors.lastname: Hor
authors.affiliation: Department of Diagnostic and Interventional Radiology, CHI St. Luke's Health, Houston, Texas, USA.
authors.forename: Raja
authors.initials: R
authors.lastname: Muthupillai
mesh_terms: D000328:Adult; D005260:Female; D057086:High-Intensity Focused Ultrasound Ablation; D006801:Humans; D007889:Leiomyoma / Q000601:surgery*; D053783:Magnetic Resonance Imaging, Interventional; D025321:Surgery, Computer-Assisted; D013814:Thermal Conductivity; D016896:Treatment Outcome; D014594:Uterine Neoplasms / Q000601:surgery*
keywords: high temperature; magnetic resonance-guided high intensity focused ultrasound; tissue thermal conductivity; uterine fibroid