A digital viscoelastic liver phantom for investigation of elastographic measurements

To develop elastography imaging technologies and implement image reconstruction algorithms, testing is done with phantoms. Although the validation step is usually taken using real data and physical phantoms, their geometry as well as composition, biomechanical parameters, and details of applying stress cannot be modified readily. Such considerations have gained increasing importance with the growth of elastography techniques as one of the non-invasive medical imaging modalities, which can map the elastic properties and stiffness of soft tissues. In this article, we develop a digital viscoelastic phantom using computed tomography (CT) imaging data and several application software tools based on illustrations of normal liver anatomy so as to investigate the biomechanics of elastography via finite element modeling (FEM). Here we discuss how to create this phantom step by step, demonstrate typical shear wave elastography (SWE) experiments of applying transient stress to the liver model, and calculate quantitative measurements. In particular, shear wave velocities are investigated through a parametric study designed based on tissue stiffness and distance from the applied stress. According to the results of FEM analysis, low errors were obtained for shear wave velocity estimation for both mechanical stress (~2-5%) and acoustic radiation force (~3-7%). Results show that our model is a powerful framework and benchmark for simulating and implementing different algorithms in shear wave elastography, which can serve as a guide for upcoming researches and assist scientists to optimize their subsequent experiments in terms of design.

[1]  Hassan Rezazadeh,et al.  Optimization of Effective Parameters on Acoustic Radiation Force Shear Waves Interference Patterns Elastography by Using a Finite Element Model , 2018 .

[2]  M Fink,et al.  A solution to diffraction biases in sonoelasticity: the acoustic impulse technique. , 1999, The Journal of the Acoustical Society of America.

[3]  J. Greenleaf,et al.  Ultrasound-stimulated vibro-acoustic spectrography. , 1998, Science.

[4]  Joon Koo Han,et al.  Magnetic resonance elastography of healthy livers at 3.0 T: Normal liver stiffness measured by SE-EPI and GRE. , 2018, European journal of radiology.

[5]  K J Parker,et al.  Tissue response to mechanical vibrations for "sonoelasticity imaging". , 1990, Ultrasound in medicine & biology.

[6]  Mallika Sridhar-Keralapura,et al.  A novel breast software phantom for biomechanical modeling of elastography. , 2012, Medical physics.

[7]  Yang Bu,et al.  Measuring Viscoelastic Properties of Living Cells , 2019, Acta Mechanica Solida Sinica.

[8]  Alireza Mirbagheri,et al.  A Finite Element Study of Ultrasound Elastography Using Shear Wave Interference Patterns Generated by Miniature Surface Sources , 2017 .

[9]  G. Trahey,et al.  On the feasibility of remote palpation using acoustic radiation force. , 2001, The Journal of the Acoustical Society of America.

[10]  K. Parker,et al.  Elastography in the management of liver disease. , 2008, Ultrasound in medicine & biology.

[11]  O. Gilja,et al.  Liver elasticity in healthy individuals by two novel shear-wave elastography systems—Comparison by age, gender, BMI and number of measurements , 2018, PloS one.

[12]  C. R. Hill,et al.  Measurement of soft tissue motion using correlation between A-scans. , 1982, Ultrasound in medicine & biology.

[13]  Robert Rohling,et al.  Dynamic elastography using delay compensated and angularly compounded high frame rate 2D motion vectors , 2010, 2010 IEEE International Ultrasonics Symposium.

[14]  Derek Abbott,et al.  Quasi-plane shear wave propagation induced by acoustic radiation force with a focal line region: a simulation study , 2016, Australasian Physical & Engineering Sciences in Medicine.

[15]  K. Parker,et al.  "Sonoelasticity" images derived from ultrasound signals in mechanically vibrated tissues. , 1990, Ultrasound in medicine & biology.

[16]  Guo-zhu Chen,et al.  Modeling Three-dimensional Ultrasonic Guided Wave Propagation and Scattering in Circular Cylindrical Structures using Finite Element Approach , 2011 .

[17]  Kathryn R Nightingale,et al.  Improving the robustness of time-of-flight based shear wave speed reconstruction methods using RANSAC in human liver in vivo. , 2010, Ultrasound in medicine & biology.

[18]  Gregg E. Trahey,et al.  A Finite Element Model of Remote Palpation of Breast Lesions Using Radiation Force: Factors Affecting Tissue Displacement , 2000, Ultrasonic imaging.

[19]  M. Fink,et al.  Shear elasticity probe for soft tissues with 1-D transient elastography , 2002, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[20]  Kevin Parker,et al.  Two-dimensional shear wave speed and crawling wave speed recoveries from in vitro prostate data. , 2011, The Journal of the Acoustical Society of America.

[21]  J. Ophir,et al.  Elastography: A Quantitative Method for Imaging the Elasticity of Biological Tissues , 1991, Ultrasonic imaging.

[22]  M. Fink,et al.  Supersonic shear imaging: a new technique for soft tissue elasticity mapping , 2004, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[23]  Ilias Gatos,et al.  Temporal stability assessment in shear wave elasticity images validated by deep learning neural network for chronic liver disease fibrosis stage assessment. , 2019, Medical physics.

[24]  Dai Fukumura,et al.  Solid stress and elastic energy as measures of tumour mechanopathology , 2016, Nature Biomedical Engineering.

[25]  Md Tauhidul Islam,et al.  A model-based approach to investigate the effect of elevated interstitial fluid pressure on strain elastography , 2018, Physics in medicine and biology.

[26]  Kenneth Hoyt,et al.  Real-time shear velocity imaging using sonoelastographic techniques. , 2007, Ultrasound in medicine & biology.

[27]  T. Krouskop,et al.  Elastic Moduli of Breast and Prostate Tissues under Compression , 1998, Ultrasonic imaging.

[28]  Armando Manduca,et al.  Fast shear compounding using robust 2-D shear wave speed calculation and multi-directional filtering. , 2014, Ultrasound in medicine & biology.

[29]  S. Ueha,et al.  Tissue hardness measurement using the radiation force of focused ultrasound , 1990, IEEE Symposium on Ultrasonics.

[30]  Kenneth Hoyt,et al.  Sonoelastographic imaging of interference patterns for estimation of shear velocity distribution in biomaterials. , 2006, The Journal of the Acoustical Society of America.

[31]  F. S. Vinson,et al.  A pulsed Doppler ultrasonic system for making noninvasive measurements of the mechanical properties of soft tissue. , 1987, Journal of rehabilitation research and development.

[32]  K. Parker,et al.  Sonoelasticity imaging: theory and experimental verification. , 1995, The Journal of the Acoustical Society of America.

[33]  Ioan Sporea,et al.  Assessing Liver Stiffness by 2-D Shear Wave Elastography in a Healthy Cohort. , 2018, Ultrasound in medicine & biology.

[34]  Kenneth Hoyt,et al.  Quantitative sonoelastography for the in vivo assessment of skeletal muscle viscoelasticity , 2008, Physics in medicine and biology.

[35]  Bo Qiang,et al.  Modeling transversely isotropic, viscoelastic, incompressible tissue-like materials with application in ultrasound shear wave elastography , 2015, Physics in medicine and biology.

[36]  S. Emelianov,et al.  Shear wave elasticity imaging: a new ultrasonic technology of medical diagnostics. , 1998, Ultrasound in medicine & biology.

[37]  I Joubert,et al.  Magnetic resonance elastography: feasibility of liver stiffness measurements in healthy volunteers at 3T. , 2012, Clinical radiology.

[38]  D. Louis Collins,et al.  Design and construction of a realistic digital brain phantom , 1998, IEEE Transactions on Medical Imaging.

[39]  K. Parker,et al.  Two-dimensional sonoelastographic shear velocity imaging. , 2008, Ultrasound in medicine & biology.

[40]  Aaron J. Engel,et al.  A new method for shear wave speed estimation in shear wave elastography , 2015, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.

[41]  Ilias Gatos,et al.  Comparison of Sound Touch Elastography, Shear Wave Elastography and Vibration-Controlled Transient Elastography in Chronic Liver Disease Assessment using Liver Biopsy as the "Reference Standard". , 2020, Ultrasound in medicine & biology.

[42]  Kenneth Hoyt,et al.  Experimental validation of acoustic radiation force induced shear wave interference patterns , 2012, Physics in medicine and biology.

[43]  Namhee Kim,et al.  Effect of Interstitial Fluid Pressure on Ultrasound Axial Strain and Axial Shear Strain Elastography , 2017, Ultrasonic imaging.

[44]  Kevin J Parker,et al.  Elasticity estimates from images of crawling waves generated by miniature surface sources. , 2014, Ultrasound in medicine & biology.

[45]  Kevin J. Parker,et al.  Corrigendum: Imaging the elastic properties of tissue: the 20 year perspective , 2012 .

[46]  S Chevret,et al.  Hepatitis C virus related cirrhosis: time to occurrence of hepatocellular carcinoma and death , 2000, Gut.

[47]  Kevin J Parker,et al.  Modeling shear waves through a viscoelastic medium induced by acoustic radiation force , 2012, International journal for numerical methods in biomedical engineering.

[48]  Mark L. Palmeri,et al.  Guidelines for Finite-Element Modeling of Acoustic Radiation Force-Induced Shear Wave Propagation in Tissue-Mimicking Media , 2017, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.