ARFI shear-wave elastography with simulation of acute urinary tract obstruction in an ex vivo porcine kidney model

Özet

PURPOSE We aimed to evaluate if acoustic radiation force impulse (ARFI) shear-wave elastography (SWE) can detect change of parenchymal stiffness in an ex vivo porcine kidney model of acute urinary tract obstruction. METHODS A total of 20 heparinized pig kidneys were investigated at 10 intrapelvic hydrostatic pressure steps (0–90 mmHg). SWE (ARFI; Virtual TouchTM IQ, Siemens) measurements were taken at three different measuring regions and in two measuring sequences using a linear ultrasonography probe (9L4, Siemens). Median values of 10 shear-wave speed (SWS) measurements were calculated for each pressure step. Logarithmic transformed median SWS values were analyzed in a linear mixed model. RESULTS SWS increased significantly with increasing intrapelvic pressure. Median SWS for all kidneys in both measuring sequences and all measuring regions was 1.47 m/s (interquartile range [IQR], 0.38 m/s) at 0 mmHg, 1.94 m/s (IQR, 0.42 m/s) at 30 mmHg, 2.07 m/s (IQR, 0.43 m/s) at 60 mmHg, 2.24 m/s (IQR, 0.49 m/s) at 90 mmHg. The correlation between pelvic pressure increase and median SWS values for the central parenchyma was significantly higher compared with the peripheral parenchyma. CONCLUSION Acutely increased renal pelvic pressure correlates with increasing SWS values in ARFI elastography in an ex vivo porcine kidney model.