Impact of (defined) hydration on renal shear wave elastography

Elastography is a noninvasive ultrasonic method for assessing the mechanical properties of tissues. In the context of renal imaging, however, this technique has not yet been established in routine clinical practice. The aim of this study was to analyze renal elastography values in healthy adults in relation to hydration status and potential, individual influencing factors. Prior to this, the most suitable anatomical location for measurement acquisition was determined.

20 healthy young adults aged 20 to 29 years were examined with a C5-1 curved array transducer using the Sequoia ultrasound system (Siemens Healthineers, Erlangen, Germany). Shear wave elastography (SWE) was performed both before and 30 minutes after ingestion of a standardized volume of 500 mL of water. SWE was conducted in the prone position on a longitudinal plane approaching from dorsal. Elastographic measurements were obtained from three superficial regions of interest (ROI) within the renal parenchyma: the upper pole, the lower pole, and the hilar region. For subsequent association analysis applying multivariable, linear mixed modelling, the most suitable measurement location was selected based on the variability of measurements and the accessibility of the respective ROI.

The hilar region was identified as the most suitable site for elastographic measurements. It was observed that fluid intake led to a smaller increase or a greater decrease in tissue stiffness in kidneys with higher baseline stiffness compared to those with lower initial values. No evidence of an influence of the recorded participant characteristics on the SWE parameters could be observed.

The study demonstrates that the extent to which SWE parameters are influenced by hydration is influenced by the baseline elasticity of the renal parenchyma. To ensure comparability and interpretability of study outcomes, standardized protocols for SWE assessments are required.

· The baseline elastographic value affected the change in elastographic values induced by fluid intake.. · No evidence of participant characteristics affecting elastographic values could be observed..

· Sowa A, Kesselmeier M, John-Kroegel U et al. Impact of (defined) hydration on renal shear wave elastography. Rofo 2026; DOI 10.1055/a-2845-4771.