title: Four-dimensional ultrasonography for therapeutic radiofrequency ablation for hepatocellular carcinoma.
abstract: OBJECTIVE
  We examined whether four-dimensional real-time flow imaging on ultrasonography (US) is valuable to display the accurate position of percutaneous radiofrequency ablation (RFA) needle in the nodule of hepatocellular carcinoma (HCC).
  
  
  METHODS
  Ten patients with 12 HCC nodules were studied; nine were infected with hepatitis C virus (HCV) and one was diagnosed as non-B non-C. Diagnosis was done by helical dynamic CT and/or celiac angiography. Tumor vascularities in the early arterial and post-vascular phases after injection of a microbubble contrast agent were assessed by real-time US scanning of coded harmonic imaging and intermittent interval-delay scanning with a wide-band power Doppler technology. Percutaneous RFA was performed with four-dimensional real-time flow imaging under US to display the accurate position of cool-tip needle.
  
  
  RESULTS
  It was possible to obtain accurate position of the needle during RFA procedure in all 12 nodules. The needle was confirmed to be inserted into the center of the tumor nodule by various angles. The simultaneous study before RFA therapy showed the inflow of arterial blood and tumor staining in all nodules at early arterial phase of coded harmonic angio on contrast-enhanced US scan. Posttreatment study to evaluate the therapeutic efficacy showed no blood flow at both early vascular and post-vascular phases. No residual blood flow was noted on early phase of CT scan with adequate safety margin. There was no discrepancy in the finding at early phase between contrast-enhanced US and dynamic CT.
  
  
  CONCLUSIONS
  It appeared that four-dimensional real-time US provided more perceptible information on the spatial relationship between RFA needle and the target lesion, and resulted in accurate therapeutic efficacy for percutaneous RFA procedure.
authors.affiliation: Department of Internal Medicine, Division of Gastroenterology and Research Center for Infectious Disease, Aichi Medical University School of Medicine, Aichi, Japan. naokiki@aichi-med-u.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Hotta
authors.forename: Tadashi
authors.initials: T
authors.lastname: Maeno
authors.forename: Minoru
authors.initials: M
authors.lastname: Ayada
authors.forename: Ken
authors.initials: K
authors.lastname: Sato
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okumura
authors.forename: Eiji
authors.initials: E
authors.lastname: Matsumoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Fukuzawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kakumu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000601:surgery*; D017115:Catheter Ablation; D003287:Contrast Media; D005260:Female; D006526:Hepatitis C / Q000150:complications; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography / Q000379:methods
chemical_list: D003287:Contrast Media