title: Evaluation using contrast-enhanced harmonic gray scale sonography after radio frequency ablation of small hepatocellular carcinoma: sonographic-histopathologic correlation.
abstract: OBJECTIVE
  To evaluate the usefulness of contrast-enhanced harmonic wideband gray scale sonographic images obtained after radio frequency-induced coagulation necrosis, we compared the morphologic and histopathologic characteristics of the ablated tumors with sonographic images of the tumors.
  
  
  METHODS
  Forty-eight patients with 72 hepatocellular carcinomas with a maximal diameter of 3 cm or less were treated percutaneously using radio frequency ablation. Six treated tumors in 4 patients were resected 1 month after ablation; the remaining 66 treated tumors were evaluated by a biopsy procedure performed with an 18-gauge fine needle 1 month after ablation. The excised tumors and biopsy specimens were then examined by histopathologic methods, and the findings were compared with those obtained on contrast-enhanced harmonic wideband gray scale sonography. Hematoxylin-eosin-stained specimens were inconclusive as to whether cellular viability remained; therefore, cell viability was determined by a positive result after histochemical (lactate dehydrogenase and nicotinamide adenine dinucleotide phosphate-diaphorase) staining.
  
  
  RESULTS
  Contrast-enhanced harmonic wideband gray scale sonography after radio frequency ablation showed residual tumor enhancement in 5 (6.9%) of the 72 tumors; the histopathologic results for these 5 tumors were also positive for tumor residue. The remaining 67 tumors (93.1%) did not show any residual tumor enhancement when examined by sonography; however, only 66 tumors did not reveal tumor residue when examined histopathologically. Contrast-enhanced harmonic wideband sonographic imaging provided results that were comparable with histopathologic findings, the criterion standard for diagnosis; the sensitivity and specificity of the sonographic images for the detection of residual tumor tissue in ablated tumors were 83.3% (5 of 6) and 100% (66 of 66), respectively.
  
  
  CONCLUSIONS
  Contrast-enhanced harmonic wideband gray scale sonography is a potentially useful technique for evaluating the therapeutic effects of radio frequency ablation on hepatocellular carcinoma.
authors.affiliation: Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 232-0024, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Morimoto
authors.forename: Akinori
authors.initials: A
authors.lastname: Nozawa
authors.forename: Kazushi
authors.initials: K
authors.lastname: Numata
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Shirato
authors.forename: Kazuya
authors.initials: K
authors.lastname: Sugimori
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kokawa
authors.forename: Naohiko
authors.initials: N
authors.lastname: Tomita
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Saitou
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Toshio
authors.initials: T
authors.lastname: Imada
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography
chemical_list: D003287:Contrast Media