2D Shear wave elastography for evaluation of renal cortex and medulla: stiffness values in healthy children

To evaluate renal cortical and medullary stiffness using 2D Shear-wave elastography (SWE) in healthy children.

In this IRB approved prospective study, we measured the stiffness of cortex and medulla of children (4 months-17 years) at the upper pole, mid pole, and lower pole in bilateral kidneys.

The median (IQR) values of renal cortex in <1 year age group was 8.7 (5.7–11.7) kPa for right and 8.7 (4.2–14.1) kPa for the left side. For 1–5 years age group, it was 7.3 (5.3–10) kPa for the right and 8.9 (6–12.3) kPa for the left side. For >5 years, it was 7.4 (5.3–11.2) kPa for the right and 9.6 (6.2–12.7) kPa for the left side. The median (IQR) values of renal medulla in <1 year age group was 7.1 (5.1–12.5) kPa for right and 6.8 (4–10.6) kPa for the left side. For 1–5 years age group, it was 7.2 (4.9–9.7) kPa for the right and 6.9 (5.6–9.9) kPa for the left side. For >5 years, it was 6.8 (5.1–9.6) kPa for the right and 7 (5–10.2) kPa for the left side. The differences in the elasticity values amongst these groups were statistically insignificant (p>0.05). There was a significant correlation between SWE values of cortex and medulla of right kidney (ρ=0.64) and of left kidney (ρ=0.61), respectively.

SWE values of renal cortical and medullary stiffness in healthy children do not correlate with age. There is a significant correlation between SWE values of cortex and medulla of the kidneys in healthy children.