Sonographic assessment of normal renal parenchymal and medullary pyramid thicknesses among children in Enugu, Southeast, Nigeria

• Sonography of RPT and MPT at the anterior longitudinal axis of the kidney is simple.
• RPT and MPT Measurements are reliable within and between experienced sonographers.
• No significant gender differences in RPT and MPT values exist in this study.
• Significant differences exist between the right and left RPT and MPT measurements.
• Normative values of RPT and MPT in relation to age in children are useful.

BackgroundRenal parenchymal thickness (RPT) and renal medullary pyramid thickness (MPT) are important renal size parameters. This study was aimed at establishing normograms for RPT and MPT with respect to age and somatometric parameters among children.MethodsThis was a cross sectional study done in Enugu, Nigeria between May 2013 and April 2014. The subjects were 512 children aged 1–17 years scanned with ultrasound equipment with 3.5 MHz and 5 MHz curvilinear transducers. The RPT was measured perpendicularly to the long axis of the kidney from the medullary papilla to the renal capsule and MPT was measured from the apex to the base of the medullary pyramid on the same plane. The age and somatometric parameters of the subjects were recorded.ResultsThe mean ± SD of RPT and MPT for the right kidney were 12.62 ± 1.67 mm and 7.10 ± 0.92 mm and the left kidney were 12.81 ± 1.7 and 7.23 ± 0.94 mm respectively. There was a significant difference between the right and left RPT and MPT (p < 0.05). The right and left RPT correlated strongly with age, body surface area (BSA), height, and weight but moderately with body mass index (BMI). A moderate positive correlation was observed between MPT and age, BSA, height, and weight. However, a weak correlation was observed between MPT and BMI.ConclusionNormograms of RPT and MPT in relation to age could be useful for grading hydronephrosis in children.