title: Sonographically observed echogenic response during intraoperative radiofrequency ablation of cirrhotic livers: pathologic correlation.
abstract: OBJECTIVE
  We performed a study to determine the correlation between the diameter of the echogenic response observed with intraoperative sonography during radiofrequency ablation of the cirrhotic liver and the mean diameter of tissue necrosis.
  
  
  METHODS
  A total of 22 intraoperative radiofrequency ablations were created in 11 cirrhotic livers. The largest diameter of the sonographically observed echogenic response surrounding and perpendicular to the radiofrequency probe was measured. The subsequent zone of necrosis observed at pathology in the hepatectomy specimens after liver transplantation was measured in three planes and compared with the measured diameter of the echogenic response.
  
  
  RESULTS
  During all except three ablations, a hyperechoic region was visualized surrounding the radiofrequency probe. The diameter of the echogenic response correlated significantly with the mean diameter of necrosis (correlation coefficient, 0.84). However, the echogenic response overestimated the minimal diameter of necrosis (mean difference, 0.8 +/- 0.4 cm) in 18 of 22 ablations and underestimated the maximum diameter of necrosis (mean difference, 0.9 +/- 0.8 cm) in 16 of 22 ablations.
  
  
  CONCLUSIONS
  The diameter of the echogenic response observed with intraoperative sonography during radiofrequency ablation of the cirrhotic liver correlates closely with the mean diameter of the subsequent area of tissue necrosis. However, the solitary diameter of the echogenic response as measured in our study was often greater than the smallest diameter and less than the largest diameter of the area of tissue necrosis. Therefore, the echogenic response associated with radiofrequency ablation of the cirrhotic liver should be viewed only as a rough approximation of the area of induced tissue necrosis; the final assessment of the adequacy of ablation should be deferred to an alternative imaging technique.
authors.affiliation: Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78284-7800, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Leyendecker
authors.forename: Gerald D
authors.initials: GD
authors.lastname: Dodd
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Halff
authors.forename: Victor A
authors.initials: VA
authors.lastname: McCoy
authors.forename: Dacia H
authors.initials: DH
authors.lastname: Napier
authors.forename: Linda G
authors.initials: LG
authors.lastname: Hubbard
authors.forename: Kedar N
authors.initials: KN
authors.lastname: Chintapalli
authors.forename: Shailendra
authors.initials: S
authors.lastname: Chopra
authors.forename: W Kenneth
authors.initials: WK
authors.lastname: Washburn
authors.forename: Robert M
authors.initials: RM
authors.lastname: Esterl
authors.forename: Francisco G
authors.initials: FG
authors.lastname: Cigarroa
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Kohlmeier
authors.forename: Francis E
authors.initials: FE
authors.lastname: Sharkey
mesh_terms: D000328:Adult; D000368:Aged; D017115:Catheter Ablation; D004301:Doppler Effect; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009336:Necrosis; D014463:Ultrasonography