title: Power Doppler sonography for hepatocellular carcinoma: factors affecting the power Doppler signals of the tumors.
abstract: OBJECTIVE
  A recent advancement in Doppler ultrasonography (US) is power Doppler for detecting low-velocity blood flow at the microvascular level with angle independence. The present study was performed to characterize the factors contributing to the power Doppler signals of hepatocellular carcinoma (HCC).
  
  
  METHODS
  Correlation of Doppler signals of HCC in 114 patients with 178 HCC nodules was analyzed in relation to the findings of CT and angiography, tumor characteristics (size, echo pattern, and histological differentiation of tumor), viral markers and severity of liver disease.
  
  
  RESULTS
  The sensitivity of power Doppler US was superior to that of CT and angiography (each p<0.05; McNemar's test). The detection rate of power Doppler signal was significantly higher in tumors with diameter > or =2 cm (vs <2 cm in diameter), and with low/mixed echo pattern (vs high echo appearance), and with moderately/poorly differentiated HCC (vs well-differentiated HCC). Univariate analysis revealed that echo pattern, tumor size and histological differentiation of HCC in addition to CT and angiographic findings were significant. Multivariate analysis showed that tumor size and differentiation were significant.
  
  
  CONCLUSIONS
  These results indicate that tumor characteristics play an important role in power Doppler signals and that these could be assessed by the presence or absence of power Doppler signals.
authors.affiliation: Department of Internal Medicine (II), University of Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Imamura
authors.forename: Y
authors.initials: Y
authors.lastname: Shiratori
authors.forename: S
authors.initials: S
authors.lastname: Shiina
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.forename: S
authors.initials: S
authors.lastname: Obi
authors.forename: T
authors.initials: T
authors.lastname: Okudaira
authors.forename: T
authors.initials: T
authors.lastname: Teratani
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: M
authors.initials: M
authors.lastname: Akahane
authors.forename: K
authors.initials: K
authors.lastname: Ohtomo
authors.forename: M
authors.initials: M
authors.lastname: Minami
authors.forename: M
authors.initials: M
authors.lastname: Omata
mesh_terms: D000792:Angiography; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D018963:Hepatitis Antigens / Q000032:analysis; D006521:Hepatitis, Chronic / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color
chemical_list: D018963:Hepatitis Antigens