title: Contrast-enhanced ultrasound (CEUS) follow-up after radiofrequency ablation or cryoablation of focal liver lesions: treated-area patterns and their changes over time.
abstract: OBJECTIVE
  To describe the early patterns of liver lesions successfully treated with radiofrequency ablation (RFA) or cryoablation (CA) and their changes over time.
  
  
  METHODS
  Twenty-two RFA-treated and 17 CA-treated patients underwent CEUS from week 1 to year 3 post-ablation. Patterns, margins and volumes of RF-induced and cryolesions were evaluated and compared over time.
  
  
  RESULTS
  After contrast enhancement, shortly after ablation, undefined margins with persistent enhancing small vessels penetrating >2 mm into the treated zone were significantly more frequent after CA (67 %) than RFA (22 %) (P < 0.02). During the arterial phase, a thin, enhancing marginal rim was seen during week 1 (T1) in around 28 % of RF lesions, while 75 % of cryolesions had thick enhancing rims (P < 0.02). The mean RF-induced lesion volume, maximum at T1 (44.1 ± 37.5 ml), shrank slowly over time, remaining clearly visible at 1 year (8.3 ± 7.4 ml). Cryolesions shrank faster (P = 0.009), from an average of 16.6 ± 7.1 ml at T1 to 1.7 ± 1.3 ml 1-year post-ablation.
  
  
  CONCLUSIONS
  RF-induced and cryolesions differ, particularly their margins and shrinkage rates. Knowing these differences allows avoidance of incomplete treatment or falsely diagnosed recurrence, especially after CA.
  
  
  CONCLUSIONS
  • Contrast-enhanced ultrasound (CEUS) provides new follow-up information following hepatic radiological inyervention. • CEUS provides good visualisation of vascular modifications after thermoablation. • RFA-induced lesions and cryoablated lesions differ. • Knowledge about RF and cryolesion patterns is essential for correct CEUS follow-up. • Cryolesions have thicker peripheral inflammatory reactions and shrink faster than RFA-induced lesions.
authors.affiliation: Radiology Department, Hôpital Pitié- Salpêtrière, AP-HP, Institut Universitaire de Cancérologie, University Pierre et Marie Curie, 47-83, Boulevard de l'Hôpital, 75651 Paris cedex 13, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Guibal
authors.forename: Caroline
authors.initials: C
authors.lastname: Bertin
authors.forename: Sophie
authors.initials: S
authors.lastname: Egels
authors.forename: Eric
authors.initials: E
authors.lastname: Savier
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Grenier
authors.forename: Olivier
authors.initials: O
authors.lastname: Lucidarme
mesh_terms: D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D003287:Contrast Media; D003452:Cryosurgery / Q000379:methods*; D005260:Female; D005602:France; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media