title: Application of imaging fusion combining contrast-enhanced ultrasound and magnetic resonance imaging in detection of hepatic cellular carcinomas undetectable by conventional ultrasound.
abstract: OBJECTIVE
  The aim of this study is to explore the value of volume navigation image fusion-assisted contrast-enhanced ultrasound (CEUS) in detection for radiofrequency ablation guidance of hepatocellular carcinomas (HCCs), which were undetectable on conventional ultrasound.
  
  
  METHODS
  From May 2012 to May 2014, 41 patients with 49 HCCs were included in this study. All lesions were detected by dynamic magnetic resonance imaging (MRI) and planned for radiofrequency ablation but were undetectable on conventional ultrasound. After a bolus injection of 2.4 ml SonoVue® (Bracco, Italy), LOGIQ E9 ultrasound system with volume navigation system (version R1.0.5, GE Healthcare, Milwaukee, WI, USA) was used to fuse CEUS and MRI images. The fusion time, fusion success rate, lesion enhancement pattern, and detection rate were analyzed.
  
  
  RESULTS
  Image fusions were conducted successfully in 49 HCCs, the technical success rate was 100%. The average fusion time was (9.2 ± 2.1) min (6-12 min). The mean diameter of HCCs was 25.2 ± 5.3 mm (mean ± SD), and mean depth was 41.8 ± 17.2 mm. The detection rate of HCCs using CEUS/MRI imaging fusion (95.9%, 47/49) was significantly higher than CEUS (42.9%, 21/49) (P < 0.05). For small HCCs (diameter, 1-2 cm), the detection rate using imaging fusion (96.9%, 32/33) was also significantly higher than CEUS (18.2%, 6/33) (P < 0.01). All HCCs displayed a rapid wash-in pattern in the arterial phase of CEUS.
  
  
  CONCLUSIONS
  Imaging fusion combining CEUS and MRI is a promising technique to improve the detection, precise localization, and accurate diagnosis of undetectable HCCs on conventional ultrasound, especially small and atypical HCCs.
authors.affiliation: Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Wen-Ping
authors.initials: WP
authors.lastname: Wang
authors.affiliation: Institute of Medical Ultrasound and Engineering, Fudan University, Shanghai, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Mao
authors.affiliation: Institute of Medical Ultrasound and Engineering, Fudan University, Shanghai, China.
authors.forename: Zheng-Biao
authors.initials: ZB
authors.lastname: Ji
authors.affiliation: Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Bei-Jian
authors.initials: BJ
authors.lastname: Huang
mesh_terms: D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000601:surgery; D017115:Catheter Ablation; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: contrast-enhanced ultrasound (CEUS); dynamic MR imaging (MRI); hepatic cellular carcinomas (HCC); undetectable; volume navigation image fusion