title: Assessment of the ablated area after radiofrequency ablation by the spread of bubbles: comparison with virtual sonography with magnetic navigation.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether bubble images after radiofrequency ablation (RFA) can predict the ablated area.
  
  
  METHODS
  The spread of bubbles 5 minutes after RFA were compared with the unenhanced area of virtual sonography with magnetic navigation in two RFA methods: expandable needle and cool-tip needle.
  
  
  RESULTS
  Thirty-one hepatocellular carcinoma nodules were treated by RFA with either an expandable needle or cool-tip needle (n=14 and n=17, respectively) and examined. In the 14 nodules treated by expandable needle, bubble images (puncture direction; r=0.833, p=0.0002, perpendicular direction; r=0.803, p=0.0005) were closely correlated with the unenhanced area of virtual sonography. On the other hand, in 17 nodules treated by cool-tip needle, there was no correlation between the bubble images and virtual sonography (puncture direction; r=0.590, p=0.0127, perpendicular direction; r=0.342, p=0.180).
  
  
  CONCLUSIONS
  The observation of bubbles with the expandable needle can accurately predict the ablated area and is helpful for assessing local control of RFA.
authors.affiliation: Second Department of Internal Medicine, Tottori University, Tottori, Japan. masakoda@grape.med.tottori-u.ac.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Koda
authors.forename: Mari
authors.initials: M
authors.lastname: Mandai
authors.forename: Tomomitu
authors.initials: T
authors.lastname: Matono
authors.forename: Takaaki
authors.initials: T
authors.lastname: Sugihara
authors.forename: Takakazu
authors.initials: T
authors.lastname: Nagahara
authors.forename: Masaru
authors.initials: M
authors.lastname: Ueki
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohyama
authors.forename: Keiko
authors.initials: K
authors.lastname: Hosho
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Murawaki
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D009339:Needles; D009364:Neoplasm Recurrence, Local; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography