부산대학교 도서관

Quantitative elastography methods based on dis-placement measurements coaxial to ARFI excitations are ad-vantageous over shear wave-based approaches in heterogeneous and anisotropic tissues, such as kidney, that confound or limit shear wave propagation. Double-Profile Intersection (DoPIo) elastography quantifies shear elasticity by tracking ARF -induced displacements using two different focal configurations, identifying the time at which the profiles intersect, and then estimating modulus from times intersect via FEM-derived models. We demonstrate herein quantitative estimates of shear modulus, elastic regional ratios (RR) between anatomical features, and elastic degree of anisotropy (DoA) using DoPIo ultrasound in dog kidneys. Three ex vivo canine kidney with no known pathologies were imaged, shear elastic modulus was estimated in the renal cortex, medulla, and crest, and DoA and RR were measured in each region and compared against ARFI peak displacements (PD). DoPIo distinguished differences in elasticity between the cortex (median and MAD $\boldsymbol{9.3\pm 3.1\ \mathbf{kPa}}$) and inner parenchymal structures $(\boldsymbol{4.8 \pm 0.9}\ \mathbf{kPa};\ \boldsymbol{p\leq 0.0077})$, and DoPIo-based DoA indicated higher shear elasticity along nephrons versus across them in the renal crest in a consistent manner as PD. Thus, DoPIo may be relevant to on-axis measurement of shear elasticity, elastic RR, and elastic DoA in heterogeneous and anisotropic kidneys.