title: Quantitative comparison of tumor vascularity of hepatocellular carcinoma after intravenous contrast agent: conventional versus harmonic power Doppler US.
abstract: BACKGROUND
  The purpose of this study was to make a quantitative comparison between conventional and harmonic power Doppler (PD) ultrasound (US) in depicting vascularity of hepatocellular carcinoma (HCC).
  
  
  METHODS
  Ten nodular HCCs in 10 patients were prospectively examined using a 2-4-MHz convex transducer and a standardized examination protocol. Serial US images were obtained before and 20, 30, 40, 50, 60, 90, 120, 150, 180, 240, and 300 s after intravenous injection of 2 g of contrast agent using conventional and harmonic PD US. The percentage of area with Doppler signal within each HCC nodule (%PDA) was calculated in each image with a PC-based image analysis program, and the results with both US techniques were compared.
  
  
  RESULTS
  In the majority of cases, %PDA was greater on conventional PD US than on harmonic PD US. Mean %PDA of 10 HCCs was significantly higher on conventional PD US than on harmonic PD US except at 20 s after injection. The highest values of mean %PDA were 34.9% in conventional PD US and 19.5% in harmonic PD US at 60 s after injection.
  
  
  CONCLUSIONS
  Area with PD signals within the HCC is smaller and the duration of effective enhancement is shorter in harmonic PD US than in conventional PD US.
authors.affiliation: Department of Radiology and the Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Park
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: A Y
authors.initials: AY
authors.lastname: Kim
authors.forename: J I
authors.initials: JI
authors.lastname: Choi
authors.forename: J K
authors.initials: JK
authors.lastname: Han
authors.forename: B I
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000000981:diagnostic imaging; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides / Q000008:administration & dosage; D011446:Prospective Studies; D018608:Ultrasonography, Doppler / Q000379:methods
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508