Validation of Vibration-Controlled Transient Elastography by means of Dynamic Mechanical Analysis: Application to in vivo / in vitro porcine liver

It is well known in clinical medicine that palpation is an effective diagnostic tool for characterizing tissues mechanical properties. This accounts for the motivation of investigators for developing quantitative elastography techniques for noninvasively evaluating the viscoelastic properties of tissues. Comparison of a new clinical measurement technique with an established one is often needed to determine whether they agree sufficiently. Dynamic Mechanical Analysis (DMA) is often considered as the reference method to characterize quantitatively mechanical properties of materials. However, DMA is an invasive technique and only in vitro mechanical properties can be estimated. In this study, a comparison between Vibration-Controlled Transient Elastography (VCTE¿) and Dynamic Mechanical Analysis techniques is performed on in vivo / in vitro porcine liver. In vitro results show that elastic properties obtained by VCTE¿ and DMA are in agreement. Results demonstrate that the liver is homogeneous, isotropic and more elastic than viscous. Besides, it is presented that viscoelastic properties obtained by VCTE¿ and DMA change significantly with postmortem time and with the boundary conditions. Finally, this work shows that VCTE¿ could be the new ¿gold standard¿ method for quantitatively assessing in vivo tissue elastic properties.