Background: Shear wave elastography (SWE) is one of the promising techniques that allow the non-invasive estimation of tissue stiffness. It is approved by Food and drug administration (FDA) in liver disease. It shows high sensitivity and specificity to differentiate normal from cirrhotic liver. While there are few studies applied on the kidney with the same technique, we performed this study to validate normal values of renal cortical elasticity in normal native kidney to differentiate normal kidneys from those with renal disease. As pSWE values above the normal values would indicate early changes in renal cortex indicating early renal disease.
Materials and methods: this study was executed at the Radio diagnosis Department, Zagazig University from June 2019 to April 2020. The study included 84 healthy volunteers (48 females and 36 males) who showed normal kidney function test by lab. examination. We examined the renal cortex with conventional ultrasound and point shear wave elastography (pSWE), measuring the Young's modulus (YMs) for the renal cortical elasticity. All analyses were done using the Statistical Package for the Social Sciences 20.0 software.
Results: The mean value of SWE (kPa) in healthy volunteers was 3.1±0.94 kPa. Both age (r=0.50; P=.000) and kidney depth (r=0.23; P=.38) showed a significant positive correlation with pSWE measurements, moderate correlation with age and mild correlation with kidney depth.
Conclusion: Our results suggest that the mean value of normal pSWE measurement of the renal cortex is 3.1±0.94 kPa. The pSWE values correlates positively with age and kidney depth.