title: Hepatitis activity should be considered a confounder of liver stiffness measured with MR elastography.
abstract: OBJECTIVE
  To evaluate the effect of hepatitis activity on liver stiffness measurements and the role of serum alanine aminotransferase (ALT) in liver fibrosis staging by MR elastography (MRE).
  
  
  METHODS
  We measured liver stiffness (kPa) in 135 patients by MRE and histologically assessed fibrosis and hepatitis activity within 2 months. Stepwise multiple linear regression was performed to determine the maximum adjusted R(2) against liver stiffness, after adjusting for nothing (model 1), ALT/upper limit of normal categories (model 2), and hepatitis activity (A grade) by METAVIR (model 3). Logistic regression was used to identify independent factors associated with pathologically proven cirrhosis.
  
  
  RESULTS
  Platelet count and METAVIR F score were strongly associated with liver stiffness. The adjusted R(2) value of model 3 (0.7026) was higher than those of models 1 (0.6472) and 2 (0.6564), showing that hepatitis activity affected liver stiffness measurement. High ALT levels (odds ratio, 0.0066; P = 0.0003) as well as MRE (odds ratio, 9.91; P < 0.0001) were independently associated with cirrhosis.
  
  
  CONCLUSIONS
  Hepatitis activity may be a confounder of liver stiffness measurement during liver fibrosis staging using MRE. MRE can potentially make an overdiagnosis of liver cirrhosis if the patient has high ALT levels.
authors.affiliation: Department of Radiology, University of Yamanashi, Yamanashi, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Tadao
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morisaka
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Sano
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Enomoto
authors.forename: Masanori
authors.initials: M
authors.lastname: Matsuda
authors.forename: Hideki
authors.initials: H
authors.lastname: Fujii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Onishi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D015986:Confounding Factors, Epidemiologic; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods / Q000706:statistics & numerical data*; D005189:False Positive Reactions; D005260:Female; D006505:Hepatitis / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007564:Japan / Q000453:epidemiology; D008099:Liver / Q000503:physiopathology*; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: activity of hepatitis; hepatic fibrosis; liver stiffness; magnetic resonance elastography