Sonographic measurements of renal size in slovenian population of children

Background: Kidney size is an important parameter for evaluating normal kidney development and growth. The purpose of our study was to determine normal range of kidney size according to age, weight and height in our population of children. Patients and methods: 591 children and adolescents referred for abdominal sonography were enrolled. There were 291 boys and 300 girls aged between 0 month and 20 years. Children with known renal disease or abnormal renal ultrasound findings were excluded from the study. The renal length, width and depth were measured on the maximal longitudinal renal diameter and on the transverse diameter at the hilar region, perpendicular to the first measurement. Each kidney was measured twice. Once with the patient in supine and once with the patient in prone position. The renal volume was calculated from the measurements. Results: There were no statistically significant differences in kidney size between boys and girls (p> 0.566). The difference in lenght between left and right kidney was small but statistically significant (p< 0.007). Left kidney was longer and had greater volume than the right one. We presented some tables with normal values of kidney length and volume according to age, body weight and body height for our population of children and young people. Conclusions: We believe that our tables with normal values of kidney length and volume will provide a useful references for kidney evaluation by ultrasonography in children. We suggest correlation with body height for the kidney length and correlation with body weight for the kidney volume evaluation.