Acoustic radiation force impulse (ARFI) elastography of kidneys in healthy adult cats: preliminary results.

OBJECTIVES: To describe acoustic radiation impulse force elastography in evaluation of kidneys of adult cats. MATERIALS AND METHODS: Ten healthy adult short-haired cats were included. Echogenicity and texture, cortico-medullary relationship, size and edges of kidney were assessed by B-mode and by qualitative elastography to detect the presence of deformities and shear velocities of different portions (cranial, middle and caudal of cortex and medulla). RESULTS: Findings of ultrasonography were normal in all cats. Qualitative elastography demonstrated that the renal cortex was not deformable and had homogeneous dark gray areas; the renal pelvis had lower stiffness (white); and the medulla showed a mosaic pattern. The results of shear wave velocity were different in cranial, middle and caudal regions of cortex and medulla: 2·46 ±0·45, 2·46 ±0·48 and 2·37 ±0·42 (P=0·795) in cortex and 1·61 ±0·69, 1·75 ±0·66 and 2·00 ±0·55 m/s (P=0·156) in medulla, respectively. CLINICAL SIGNIFICANCE: Quantitative and qualitative acoustic radiation impulse force elastography of the kidney in adult cats was easily performed and this study provides base line data to allow the use of acoustic radiation impulse force in diseased animals.