title: Shear wave dispersion in lean versus steatotic rat livers.
abstract: OBJECTIVE
  The precise measurement of fat accumulation in the liver, or steatosis, is an important clinical goal. Our previous studies in phantoms and mouse livers support the hypothesis that, starting with a normal liver, increasing accumulations of microsteatosis and macrosteatosis will increase the lossy viscoelastic properties of shear waves in a medium. This increase results in an increased dispersion (or slope) of the shear wave speed in the steatotic livers.
  
  
  METHODS
  In this study, we moved to a larger animal model, lean versus obese rat livers ex vivo, and a higher-frequency imaging system to estimate the shear wave speed from crawling waves.
  
  
  RESULTS
  The results showed elevated dispersion in the obese rats and a separation of the lean versus obese liver parameters in a 2-dimensional parameter space of the dispersion (slope) and shear wave speed at a reference frequency of 150 Hz.
  
  
  CONCLUSIONS
  We have confirmed in 3 separate studies the validity of our dispersion hypothesis in animal models.
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Barry
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Christopher
authors.initials: C
authors.lastname: Hazard
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Zaegyoo
authors.initials: Z
authors.lastname: Hah
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Alexander
authors.initials: A
authors.lastname: Partin
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Robert A
authors.initials: RA
authors.lastname: Mooney
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Kuang-Hsiang
authors.initials: KH
authors.lastname: Chuang
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Wenqing
authors.initials: W
authors.lastname: Cao
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.).
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Rubens
authors.affiliation: Departments of Surgery (C.T.B., K.-H.C.), Pathology and Laboratory Medicine (R.A.M., W.C.), and Radiology (D.J.R.), University of Rochester Medical Center, Rochester, New York USA; GE Global Research, Niskayuna, New York USA (C.H.); Department of Electrical and Computer Engineering (Z.H., A.P., K.J.P.), University of Rochester, Rochester, New York USA; and GE Global Research, Shanghai, China (G.C.). kevin.parker@rochester.edu.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Parker
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005234:Fatty Liver / Q000000981:diagnostic imaging*; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D051381:Rats; D014463:Ultrasonography
keywords: dispersion; fatty liver; medical ultrasound; shear waves; steatosis