Background: Ultrasonography rapidly measures the sizes of visceral organs, such as the kidneys, without exposing the patient to ionizing radiation. Various disorders alter kidney size, requiring the availability of a reliable reference for measuring kidney length of children for clinical evaluation.

Objective: To determine normal renal lengths of healthy Thai children and to generate normal renal-length growth pattern according to gender, age, body weight, height, body mass index, and body surface area.

Materials and Methods: Ultrasonography examinations of 726 full-term neonates through children younger than 14 years of age were conducted between 2016 and 2020. The data were divided by age group. Retrospective data were gathered from computerized archives and patients’ records.

Results: The present study was an analysis of 726 subjects that revealed that their left kidneys were longer than their right (p<0.001). Height significantly correlated with kidney length (right kidney: R²=0.866, p<0.001; left kidney: R²=0.862, p<0.001). Kidney length varied as a function of gender, as bilateral kidneys were longer in boys versus girls, and the differences in kidney length significantly differed.

Conclusion: The normal size of kidneys of each age group and correlation maps developed in the present study should aid radiologists andclinician to identify diseases of children that cause changes in kidney size.

Keywords: Renal length; Renal size; Ultrasound; Kidney

DOI: 10.35755/jmedassocthai.2023.01.13740

Received 7 March 2022 | Revised 7 November 2022 | Accepted 22 November 2022