title: B-mode ultrasound with algorithm based on statistical analysis of signals: evaluation of liver fibrosis in patients with chronic hepatitis C.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the degree of liver fibrosis in patients with chronic hepatitis C by use of a method in which the homogeneity of the tissue texture of the liver on B-mode ultrasound images is analyzed on the basis of results of a statistical chi-square test of the echo amplitudes. The method includes an algorithm for removing small structures, such as cross sections of the thin vessels, in the background texture to minimize differences in analysis results between users.
  
  
  METHODS
  Analysis was performed on images of 148 patients with histologically proven chronic hepatitis C without cirrhosis. The peak value of the C(m)(2) (modified chi-square distribution) histogram was calculated from B-mode ultrasound images, and the resulting value was compared with the histologic fibrosis grade.
  
  
  RESULTS
  The peak C(m)(2) histogram value for grade F3 fibrosis was higher than that for grades F0 and F1 (p < 0.0001) and F2 (p = 0.0003). The value for grade F2 was higher than that for grades F0 and F1 (p = 0.0027). The values gradually increased with an increase in liver fibrosis grade, although no difference was found between grades F0 and F1.
  
  
  CONCLUSIONS
  The grades of liver fibrosis in patients with chronic hepatitis C are well discriminated with the B-mode ultrasound-based analysis algorithm without discrimination between grades F0 and F1. Findings on conventional ultrasound images may reflect progression of liver fibrosis even in the absence of cirrhosis.
authors.affiliation: Department of Gastroenterology, Ogaki Municipal Hospital, 4-86 Minaminokawa, Ogaki, Gifu 503-8502, Japan. tkumada@he.mirai.ne.jp
authors.forename: Hidenori
authors.initials: H
authors.lastname: Toyoda
authors.forename: Takashi
authors.initials: T
authors.lastname: Kumada
authors.forename: Naohisa
authors.initials: N
authors.lastname: Kamiyama
authors.forename: Katsuya
authors.initials: K
authors.lastname: Shiraki
authors.forename: Kojiro
authors.initials: K
authors.lastname: Takase
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hachiya
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003627:Data Interpretation, Statistical; D005260:Female; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*