title: Assessment of Liver Fibrosis with Diffusion-Weighted Magnetic Resonance Imaging Using Different b-values in Chronic Viral Hepatitis.
abstract: OBJECTIVE
  To examine the effectiveness of apparent diffusion coefficient (ADC) values and to compare the reliability of different b-values in detecting and identifying significant liver fibrosis.
  
  
  METHODS
  There were 44 patients with chronic viral hepatitis (CVH) in the study group and 30 healthy participants in the control group. Diffusion-weighted magnetic resonance imaging (DWI) was performed before the liver biopsy in patients with CVH. The values of ADC were measured with 3 different b-values (100, 600, 1,000 s/mm2). In addition, liver fibrosis was classified using the modified Ishak scoring system. Liver fibrosis stages and ADC values were compared using areas under the receiver-operating characteristic (ROC) curve.
  
  
  RESULTS
  The study group's mean ADC value was not statistically significantly different from the control group's mean ADC value at b = 100 s/mm2 (3.69 ± 0.5 × 10-3 vs. 3.7 ± 0.3 × 10-3 mm2/s) and b = 600 s/mm2 (2.40 ± 0.3 × 10-3 vs. 2.5 ± 0.5 × 10-3 mm2/s). However, the study group's mean ADC value (0.99 ± 0.3 × 10-3 mm2/s) was significantly lower than that of the control group (1.2 ± 0.1 × 10-3 mm2/s) at b = 1,000 s/mm2. With b = 1,000 s/mm2 and the cutoff ADC value of 0.0011 mm2/s for the diagnosis of liver fibrosis, the mean area under the ROC curve was 0.702 ± 0.07 (p = 0.0015). For b = 1,000 s/mm2 and the cutoff ADC value of 0.0011 mm2/s to diagnose significant liver fibrosis (Ishak score = 3), the mean area under the ROC curve was 0.759 ± 0.07 (p = 0.0001).
  
  
  CONCLUSIONS
  Measurement of ADC values by DWI was effective in detecting liver fibrosis and accurately identifying significant liver fibrosis when a b-value of 1,000 s/mm2 was used.
authors.affiliation: Department of Radiology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey.
authors.forename: Ercan
authors.initials: E
authors.lastname: Kocakoc
authors.forename: Ayse Ahsen
authors.initials: AA
authors.lastname: Bakan
authors.forename: Orhan Kursat
authors.initials: OK
authors.lastname: Poyrazoglu
authors.forename: Adile Ferda
authors.initials: AF
authors.lastname: Dagli
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Gul
authors.forename: Mehtap
authors.initials: M
authors.lastname: Cicekci
authors.forename: Ibrahim Halil
authors.initials: IH
authors.lastname: Bahcecioglu
mesh_terms: D000328:Adult; D001706:Biopsy; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019694:Hepatitis B, Chronic / Q000473:pathology*; D019698:Hepatitis C, Chronic / Q000473:pathology*; D006801:Humans; D008103:Liver Cirrhosis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results