title: Development of oil-in-gelatin phantoms for viscoelasticity measurement in ultrasound shear wave elastography.
abstract: Because tissues consist of solid and fluid materials, their mechanical properties should be characterized in terms of both elasticity and viscosity. Although the elastic properties of tissue-mimicking phantoms have been extensively studied and well characterized in commercially available phantoms, their viscous properties have not been fully investigated. In this article, a set of 14 tissue-mimicking phantoms with different concentrations of gelatin and castor oil were fabricated and characterized in terms of acoustic and viscoelastic properties. The results indicate that adding castor oil to gelatin phantoms decreases shear modulus, but increases shear wave dispersion. For 3% gelatin phantoms containing 0%, 10%, 20% and 40% oil, the measured shear moduli are 2.01 ± 0.26, 1.68 ± 0.25, 1.10 ± 0.22 and 0.88 ± 0.17 kPa, and the Voigt-model coupled shear viscosities are 0.60 ± 0.11, 0.89 ± 0.07, 1.05 ± 0.11 and 1.06 ± 0.13 Pa·s, respectively. The results also confirm that increasing the gelatin concentration increases shear modulus. For phantoms containing 3%, 4%, 5%, 6% and 7% gelatin, the measured shear moduli are 2.01 ± 0.26, 3.10 ± 0.34, 4.18 ± 0.84, 8.05 ± 1.00 and 10.24 ± 1.80 kPa at 0% oil and 1.10 ± 0.22, 1.97 ± 0.20, 3.13 ± 0.63, 4.60 ± 0.60 and 8.43 ± 1.39 kPa at 20% oil, respectively. The phantom recipe developed in this study can be used in validating ultrasound shear wave elastography techniques for soft tissues.
authors.affiliation: Philips Research North America, Briarcliff Manor, New York, USA; University of Southern California, University Park Campus, Los Angeles, California, USA.
authors.forename: Man M
authors.initials: MM
authors.lastname: Nguyen
authors.forename: Shiwei
authors.initials: S
authors.lastname: Zhou
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Robert
authors.forename: Vijay
authors.initials: V
authors.lastname: Shamdasani
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis; D002368:Castor Oil / Q000737:chemistry*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005780:Gelatin / Q000737:chemistry*; D008422:Materials Testing; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength; D014783:Viscosity
chemical_list: D002368:Castor Oil; D005780:Gelatin
keywords: Oil-in-gelatin phantom; Shear modulus; Shear viscosity; Shear wave dispersion; Shear wave elastography; Ultrasound elastography; Viscoelasticity