In this study, we extend our previously developed shear modulus reconstruction methods [1] such that arbitrary internal mechanical sources (i.e., expressed as a static or dynamic pressure or a force vector in a region of interest) can be reconstructed together with the shear modulus. Originally, the methods assume that mechanical sources exist outside an ROI (i.e., external sources). We also propose to deal with an internal mechanical source combined with other unknowns basically except for a shear modulus, i.e., inertia, mean normal stress etc. For the purpose of the shear modulus reconstruction, such reconstructions decrease the computational time. The feasibility of the reconstruction methods is verified through simulations. These extensions of the reconstruction methods will increase the applications of a shear modulus reconstruction. Moreover, the reconstruction of the mechanical source will also be used as an estimate of the point spread function for designing US beamformer, controlling tissue deformation (i.e., elasticity imaging), HIFU treatment etc. Now, an arbitrary internal mechanical source can be dealt with together with shear modulus (e.g., high intensity focus ultrasound, static compressor, vibrator, heart motion, pulsation, etc).
[1] C. Sumi, Acoustical Imaging, vol. 29, 59-68, 2008.