Assessment of Kidney Stiffness in a Swine Model of Renal Arterial Stenosis with 7-D MR Elastography

Meng Yin¹, Lizette Warner², Lilach O. Lerman², Armando Manduca¹, Richard L. Ehman¹

7-D MR Elastography (MRE) acquisition involves obtaining displacement data for 3 dimensions in space, 3 cyclic displacement directions at each point in space, and at multiple time points in the wave cycle. We observed that 7-D MRE provides renal parenchymal stiffness measurements that have similar mean values but a smaller standard deviation than 2-D measurements for the same kidney in a porcine model of acute renal artery stenosis. It is sufficiently sensitive to detect expected reactive stiffness changes in the contralateral kidney in an experimental animal model of RAS. It also provides motivation for further development of 7-D MRE techniques.