Normal sonographic renal length measurements in an Australian pediatric population

Background Reference charts depicting normal growth are important for the sonographic assessment of the pediatric kidney. Limited charts are available for clinical use in an Australian population. Objective To retrospectively collate sonographic renal length measurements in a cohort of low-risk Australian children aged newborn to 16 years to produce a reference table and comparison with other published charts. Materials and methods We identified consecutive pediatric patients who were at low risk for renal disease and had renal lengths measured. After exclusions, we included 941 renal lengths (male 490, female 451). We used linear regression to estimate the relationship of renal length with age, gender and side. We calculated percentile values of renal length according to age categories. Results No statistically significant differences in mean renal length were observed between males and females, or for left and right kidneys. We tabulated reference data and provide them in a reference chart (1-, 2.5-, 5-, 10-, 50-, 90-, 97.5- and 99-percentiles). Conclusion We calculated new reference ranges for pediatric renal length using a larger cohort than previously published, from a population with diverse ethnicity.