title: Comparison of temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna: results in ex vivo porcine livers.
abstract: OBJECTIVE
  To compare temperature curve and ablation zone between 915- and 2450-MHz cooled-shaft microwave antenna in ex vivo porcine livers.
  
  
  METHODS
  The 915- and 2450-MHz microwave ablation and thermal monitor system were used in this study. A total of 56 ablation zones and 280 temperature data were obtained in ex vivo porcine livers. The output powers were 50, 60, 70, and 80 W and the setting time was 600 s. The temperature curve of every temperature spot, the short- and long-axis diameters of the coagulation zones were recorded and measured.
  
  
  RESULTS
  At all four power output settings, the peak temperatures of every temperature spot had a tendency to increase accordingly as the MW output power was increased, and except for 5mm away from the antenna, the peak temperatures for the 915 MHz cooled-shaft antenna were significantly higher than those for the 2450 MHz cooled-shaft antenna (p<0.05). Meanwhile, the short- and long-axis diameters for the 915 MHz cooled-shaft antenna were significantly larger than those for the 2450 MHz cooled-shaft antenna (p<0.05).
  
  
  CONCLUSIONS
  The 915 MHz cooled-shaft antenna can yield a significantly larger ablation zone and achieve higher temperature in ablation zone than a 2450 MHz cooled-shaft antenna in ex vivo porcine livers.
authors.affiliation: Department of Ultrasound, The General Hospital of Jinan Military Region, Jinan 250031, China. syymail@126.com
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Cheng
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Guoming
authors.initials: G
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Liang
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D003080:Cold Temperature; D066298:In Vitro Techniques; D008099:Liver / Q000601:surgery*; D008872:Microwaves / Q000627:therapeutic use*; D013552:Swine