MRE is a novel tool to study in-vivo biomechanics. Recently, the diagnostic value of viscosity has been explored. However, its physical origin as intrinsic absorption or due to scattering is yet unknown. This work shows that the majority of viscosity at about 100Hz is apparent, thus originating mainly from scattering. Moreover, we observed that the classical springpot model fails to describe the dispersion properties of complex media containing scattering structures. We propose a nonlocal viscoelastic model that can ultimately disentangle intrinsic loss effects from scattering-induced ones. This changes dramatically the way we interpret viscous changes for therapies impacting on vasculature.