Christopher T Barry1, Christopher Hazard1, Zaegyoo Hah1, Gang Cheng1, Alexander Partin1, Robert A Mooney1, Kuang-Hsiang Chuang1, Wenqing Cao1, Deborah J Rubens1, Kevin J Parker2. 1. 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.). 2. 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.
Abstract
OBJECTIVES: 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.
OBJECTIVES: 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 obeserat 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 obeserats 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.