title: Investigating liver stiffness and viscosity for fibrosis, steatosis and activity staging using shear wave elastography.
abstract: OBJECTIVE
  Quantitative shear wave elastography was shown to be an effective tool for the non-invasive diagnosis and staging of chronic liver diseases. The liver shear modulus, estimated from the propagation velocity of shear waves, is correlated to the degree of fibrosis and can therefore be used for the non-invasive staging of fibrosis.
  
  
  METHODS
  We performed a clinical prospective study in a total of 120 patients with various chronic liver diseases to compare the accuracy of supersonic shear imaging (SSI), a technique based on acoustic radiation and ultrafast ultrasound imaging, to 1D transient elastography (FibroScan) for the staging and grading of fibrosis as assessed by liver biopsy. Since shear wave propagation spectroscopy can also provide additional mechanical information on soft tissues, such as viscosity, we also investigated those new mechanical parameters as possible predictors of fibrosis, steatosis, and disease activity.
  
  
  RESULTS
  SSI was successfully performed in 98.3% of patients and it was shown to be as accurate as FibroScan for the staging of fibrosis both for the whole population (N=120) and for the subgroup with viral hepatitis (n=70) (AUC=0.85 [0.77-0.96] and 0.89 [0.81-0.97] for significant fibrosis, AUC=0.90 [0.83-0.97] and 0.87 [0.75-0.98] for cirrhosis, with respect to SSI [n=68/70] and FibroScan [n=66/68]). Viscosity could also be used to stage the degree of fibrosis (AUC=0.76 [0.64-0.87] for significant fibrosis and AUC=0.87 [0.74-0.99] for cirrhosis), for the subgroup of patients with viral hepatitis (n=67/70) but was a poor predictor of disease activity and steatosis levels.
  
  
  CONCLUSIONS
  Supersonic shear imaging is a robust technique for the staging of liver fibrosis. Liver viscosity was found to be correlated with fibrosis but not to steatosis or disease activity.
authors.affiliation: Institut Langevin, ESPCI ParisTech, PSL University, CNRS UMR7587, INSERM U979, Paris, France. Electronic address: thomas.deffieux@espci.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Deffieux
authors.affiliation: Institut Langevin, ESPCI ParisTech, PSL University, CNRS UMR7587, INSERM U979, Paris, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Gennisson
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Bousquet
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Corouge
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Simona
authors.initials: S
authors.lastname: Cosconea
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Dalila
authors.initials: D
authors.lastname: Amroun
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Simona
authors.initials: S
authors.lastname: Tripon
authors.affiliation: Service d'anatomo-pathologie, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Terris
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mallet
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Sogni
authors.affiliation: Institut Langevin, ESPCI ParisTech, PSL University, CNRS UMR7587, INSERM U979, Paris, France.
authors.forename: Mickael
authors.initials: M
authors.lastname: Tanter
authors.affiliation: Liver Unit, Hôpital Cochin, APHP, INSERM U1016, Université Paris-Descartes, Paris, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Pol
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002908:Chronic Disease; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005234:Fatty Liver / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D014783:Viscosity; D055815:Young Adult
keywords: Elastography; Fibrosis; Liver biopsies; Liver stiffness; Non-invasive markers of fibrosis; Shear wave; Shear wave spectroscopy; Steatosis