title: Differential diagnosis of hepatic tumors by using contrast enhancement patterns at US.
abstract: OBJECTIVE
  To assess the accuracy of pattern-based classification of contrast material-enhanced wideband harmonic gray-scale ultrasonographic (US) images in the differential diagnosis of hepatic tumors.
  
  
  METHODS
  A total of 183 hepatic lesions in 183 patients were studied; lesions included 116 hepatocellular carcinomas, 42 liver metastases, and 25 liver hemangiomas. After injection of a galactose-palmitic acid contrast agent, lesions were scanned with contrast-enhanced wideband harmonic gray-scale US in the arterial, portal venous, and late venous phases. The enhancement patterns were classified, and multiple logistic regression analysis was used to identify diagnostic patterns that enabled differentiation between hepatic tumors.
  
  
  RESULTS
  Five enhancement patterns were found to be significant in predicting different hepatic tumors. In hepatocellular carcinomas, the presence of intratumoral vessels in the arterial phase and homogeneous or heterogeneous enhancement in the portal phase were the most typical patterns. In metastases, the absence of intratumoral vessels in the arterial phase and ring enhancement or a perfusion defect in the portal phase were the most typical patterns. In hemangiomas, the absence of intratumoral vessels in the arterial phase and peripheral nodular enhancement in the portal phase were the most typical patterns. The sensitivity, specificity, and accuracy of diagnosis based on combinations of enhancement patterns were, respectively, 94.8%, 94.0%, and 94.5% for hepatocellular carcinoma; 90.5%, 94.3%, and 93.4% for metastasis; and 88.0%, 99.4%, and 97.8% for hemangioma.
  
  
  CONCLUSIONS
  Contrast-enhanced wideband harmonic gray-scale US is a useful tool for differentiating among the hepatic tumors studied.
authors.affiliation: Third Department of Internal Medicine, Yokohama City University School of Medicine, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Isozaki
authors.forename: Kazushi
authors.initials: K
authors.lastname: Numata
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kiba
authors.forename: Koji
authors.initials: K
authors.lastname: Hara
authors.forename: Manabu
authors.initials: M
authors.lastname: Morimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Hisahiko
authors.initials: H
authors.lastname: Sekihara
authors.forename: Toru
authors.initials: T
authors.lastname: Kubota
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimada
authors.forename: Toshio
authors.initials: T
authors.lastname: Morizane
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D005690:Galactose; D006391:Hemangioma / Q000000981:diagnostic imaging; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D019308:Palmitic Acid; D012680:Sensitivity and Specificity; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D019308:Palmitic Acid; D005690:Galactose