title: Assessment of hepatic fibrosis with magnetic resonance elastography.
abstract: OBJECTIVE
  Accurate detection of hepatic fibrosis is crucial for assessing prognosis and candidacy for treatment in patients with chronic liver disease. Magnetic resonance (MR) elastography, a technique for quantitatively assessing the mechanical properties of soft tissues, has been shown previously to have potential for noninvasively detecting liver fibrosis. The goal of this work was to obtain preliminary estimates of the sensitivity and specificity of the technique in diagnosing liver fibrosis, and to assess its potential for identifying patients who potentially can avoid a biopsy procedure.
  
  
  METHODS
  MR elastography was performed in 35 normal volunteers and 50 patients with chronic liver disease. MR imaging measurements of hepatic fat to water ratios were obtained to assess the potential for fat infiltration to affect stiffness-based detection of fibrosis.
  
  
  RESULTS
  Liver stiffness increased systematically with fibrosis stage. Receiver operating curve analysis showed that, with a shear stiffness cut-off value of 2.93 kilopascals, the predicted sensitivity and specificity for detecting all grades of liver fibrosis is 98% and 99%, respectively. Receiver operating curve analysis also provided evidence that MR elastography can discriminate between patients with moderate and severe fibrosis (grades 2-4) and those with mild fibrosis (sensitivity, 86%; specificity, 85%). Hepatic stiffness does not appear to be influenced by the degree of steatosis.
  
  
  CONCLUSIONS
  MR elastography is a safe, noninvasive technique with excellent diagnostic accuracy for assessing hepatic fibrosis. Based on the high negative predictive value of MR elastography, an initial clinical application may be to triage patients who are under consideration for biopsy examination to assess possible hepatic fibrosis.
authors.affiliation: Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Yin
authors.forename: Jayant A
authors.initials: JA
authors.lastname: Talwalkar
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.forename: Armando
authors.initials: A
authors.lastname: Manduca
authors.forename: Roger C
authors.initials: RC
authors.lastname: Grimm
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Rossman
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Fidler
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index