title: Portable high-intensity focused ultrasound system with 3D electronic steering, real-time cavitation monitoring, and 3D image reconstruction algorithms: a preclinical study in pigs.
abstract: OBJECTIVE
  The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms.
  
  
  METHODS
  To address the accuracy of the transducer, hydrophones in a water chamber were used to assess the generation of sonic fields. An animal study was also performed in five pigs by ablating in vivo thighs by single-point sonication (n=10) or volume sonication (n=10) and ex vivo kidneys by single-point sonication (n=10). Histological and statistical analyses were performed.
  
  
  RESULTS
  In the hydrophone study, peak voltages were detected within 1.0 mm from the targets on the y- and z-axes and within 2.0-mm intervals along the x-axis (z-axis, direction of ultrasound propagation; y- and x-axes, perpendicular to the direction of ultrasound propagation). Twenty-nine of 30 HIFU sessions successfully created ablations at the target. The in vivo porcine thigh study showed only a small discrepancy (width, 0.5-1.1 mm; length, 3.0 mm) between the planning ultrasonograms and the pathological specimens. Inordinate thermal damage was not observed in the adjacent tissues or sonic pathways in the in vivo thigh and ex vivo kidney studies.
  
  
  CONCLUSIONS
  Our study suggests that this new USg-HIFU system may be a safe and accurate technique for ablating soft tissues and encapsulated organs.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Choi
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Eui Jin
authors.initials: EJ
authors.lastname: Hwang
authors.forename: Inpyeong
authors.initials: I
authors.lastname: Hwang
authors.forename: Sungmin
authors.initials: S
authors.lastname: Woo
authors.forename: Chang Joo
authors.initials: CJ
authors.lastname: Lee
authors.forename: Eun-Joo
authors.initials: EJ
authors.lastname: Park
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi