title: Fusion imaging-guided radiofrequency ablation for hepatocellular carcinomas not visible on conventional ultrasound.
abstract: OBJECTIVE
  The objective of our study was to assess whether fusion imaging of conventional ultrasound and liver CT or MR images can improve the conspicuity of lesions and feasibility of percutaneous radiofrequency ablation (RFA) for the treatment of hepatocellular carcinomas (HCCs) not visible on ultrasound. Whether peritumoral anatomic landmarks can be used for the placement of an electrode in HCCs not visible on ultrasound even after image fusion was also evaluated.
  
  
  METHODS
  Planning ultrasound for percutaneous RFA was performed using conventional ultrasound first and then using fusion imaging later during the same session. The visibility of HCCs and feasibility of RFA on conventional ultrasound and on fusion imaging were assessed. We evaluated how many HCCs initially not visible on conventional ultrasound could be visualized and ablated after applying the fusion imaging technique. One hundred twenty HCCs not visible on conventional ultrasound in 96 patients were included.
  
  
  RESULTS
  When fusion imaging was applied, 38 of the 120 (31.7%) HCCs that were initially not visible could be seen and RFA was feasible. Among the remaining 82 HCCs still not visible after image fusion, 26 (31.7%) were ablated under the guidance of fusion imaging the technique based on peritumoral anatomic landmarks. Overall, 64 of 120 (53.3%) HCCs (59.4%, 57 of 96 patients) not visible on conventional ultrasound could be ablated under the guidance of the fusion imaging technique.
  
  
  CONCLUSIONS
  Fusion imaging can improve the conspicuity of HCCs and the feasibility of percutaneous RFA of HCCs not visible on conventional ultrasound. Peritumoral anatomic landmarks can be used for electrode placement in HCCs that are still not visible even after image fusion.
authors.affiliation: 1 All authors: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Republic of Korea.
authors.forename: Kyoung Doo
authors.initials: KD
authors.lastname: Song
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.forename: Dong Ik
authors.initials: DI
authors.lastname: Cha
authors.forename: Yousun
authors.initials: Y
authors.lastname: Chong
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography