Revealing the Origin of Attenuation in Tissue: Pure Absorption or Multiple Scattering?

Ralph Sinkus¹, Sverre Holm², Bojan Guzina³, Sven Peter Nsholm², Philippe Garteiser¹, Sabrina Doblas¹, Bernard E. Van Beers¹, Valrie Vilgrain¹

At present, the origin of the power-law behaviour of the tissues complex shear modulus in the frequency domain is not understood. Multiple-scattering theories do provide a physical explanation for this phenomenon but require that very-short-delay multiple reflections do occur. We demonstrate via in-vivo transient MR-Elastography for the first time that that very-short-delay multiple reflections are present in liver tissue and that they are absent in a silicon phantom. This sets the basis for further research investigating whether the predicted link between the spatial distribution of reflection coefficients and the observed dispersive behaviour of G* indeed holds.