title: Colour doppler ultrasonography provides real-time microwave field visualisation in an ex vivo porcine model.
abstract: BACKGROUND
  Microwave ablation (MWA) uses non-ionising thermal energy to cause cell death by coagulative necrosis. Colour Doppler ultrasound (US) produces a spherical image during tissue ablation that appears to approximate the microwave near field (MNF) in shape and size. The aim of the present study was to determine whether colour Doppler US images observed during microwave ablation correlate with the actual thermocoagulation zone (TCZ) observed in liver tissue.
  
  
  METHODS
  Twenty MWAs were performed in ex vivo bovine liver using a 915-MHz ablation antenna set to 45 W for 6 min concomitant with Doppler US imaging. The edges of spherical images observed with colour Doppler US were marked circumferentially in the tissue. The tissue was transected parallel to the angle of antenna insertion, and the distances between methylene blue markings and the TCZ were measured.
  
  
  RESULTS
  The images observed using colour Doppler US were similar in size and shape to the actual TCZ observed in the tissue. The mean distance between the observed colour Doppler US field diameter and the measured TCZ was 2 ± 1 mm.
  
  
  CONCLUSIONS
  Using colour Doppler US, the visualised field during MWA correlates with the TCZ in an ex vivo bovine liver model. Real-time, dynamic feedback of the treatment area may increase the effectiveness of MWA for liver tumours in vivo.
authors: Section of HepatoPancreatoBiliary Surgery, Department of General Surgery, Carolinas Medical Center, Charlotte, NC 28204, USA.
authors: Jim F
authors: JF
authors: Byrd
authors: Neal
authors: N
authors: Agee
authors: Iain H
authors: IH
authors: McKillop
authors: David
authors: D
authors: Sindram
authors: John B
authors: JB
authors: Martinie
authors: David A
authors: DA
authors: Iannitti
references: Surg Clin North Am. 2010 Aug;90(4):863-76
references: 20637953
references: Eur J Surg Oncol. 2010 Mar;36(3):264-8
references: 19880269
references: J Surg Oncol. 2007 Nov 1;96(6):481-6
references: 17654527
references: Radiology. 2006 Apr;239(1):269-75
references: 16493013
references: AJR Am J Roentgenol. 2006 Oct;187(4):W333-40
references: 16985103
references: Liver Int. 2008 Aug;28(7):911-21
references: 18564212
references: J Gastrointest Surg. 2008 Mar;12(3):463-7
references: 17805939
references: J Surg Res. 2009 May 15;153(2):263-7
references: 18486149
references: Int J Surg. 2008;6 Suppl 1:S65-9
references: 19186116
references: Ann Surg Oncol. 2003 Apr;10(3):275-83
references: 12679313
references: Radiographics. 2005 Oct;25 Suppl 1:S69-83
references: 16227498
references: HPB (Oxford). 2007;9(2):120-4
references: 18333126
references: Pathology. 2009 Feb;41(2):168-72
references: 19152189