title: Early detection of nonalcoholic steatohepatitis in patients with nonalcoholic fatty liver disease by using MR elastography.
abstract: OBJECTIVE
  To investigate the diagnostic accuracy (area under the receiver operating characteristic curve [AUROC]) of magnetic resonance (MR) elastography for the early detection of nonalcoholic steatohepatitis (NASH) among patients with nonalcoholic fatty liver disease (NAFLD).
  
  
  METHODS
  An institutional review board-approved and HIPAA-compliant retrospective study was conducted in 58 NAFLD patients. Informed consent was waived by the review board. Hepatic stiffness, relative fat fraction, inflammation grade, and fibrosis stage were assessed from MR elastography, in-phase and out-of-phase gradient-echo imaging, and liver biopsy histopathologic review, respectively. Pairwise t testing, receiver operating characteristic analysis, and partial correlation analysis were performed.
  
  
  RESULTS
  The mean hepatic stiffness for patients with simple steatosis (2.51 kPa) was less (P = .028) than that for patients with inflammation but no fibrosis (3.24 kPa). The mean hepatic stiffness for patients with inflammation but no fibrosis was less (P = .030) than that for patients with hepatic fibrosis (4.16 kPa). Liver stiffness had high accuracy (AUROC = 0.93) for discriminating patients with NASH from those with simple steatosis, with a sensitivity of 94% and a specificity 73% by using a threshold of 2.74 kPa.
  
  
  CONCLUSIONS
  In patients with NAFLD, hepatic stiffness measurements with MR elastography can help identify individuals with steatohepatitis, even before the onset of fibrosis; NAFLD patients with inflammation but no fibrosis have greater liver stiffness than those with simple steatosis and lower mean stiffness than those with fibrosis.
authors: Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA.
authors: Jun
authors: J
authors: Chen
authors: Jayant A
authors: JA
authors: Talwalkar
authors: Meng
authors: M
authors: Yin
authors: Kevin J
authors: KJ
authors: Glaser
authors: Schuyler O
authors: SO
authors: Sanderson
authors: Richard L
authors: RL
authors: Ehman
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001706:Biopsy; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005234:Fatty Liver / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D012372:ROC Curve; D012189:Retrospective Studies