Evaluation of 123I-orthoiodohippurate single kidney clearance rate by renal sequential scintigraphy in a large cohort of likely normal subjects aged between 0 and 18 years

Purpose Age-related values of 123I-orthoiodohippurate (OIH) single kidney clearance rate (Cl) were estimated in a large cohort of likely normal children aged between 0 and 18 years. Methods Among 4,111 children examined in the past 10 years, 917 were selected with the following inclusion criteria: (a) mild ultrasonographic hydronephrosis with right differential renal function (DRF) 47% (498 pts), (b) known or suspected urinary tract infection with normal ultrasound, serum creatinine and DMSA and DRF 47% (419 pts). 123I-OIH-Cl was assessed using a validated gamma camera method. Children were divided into 21 age classes: from 0 to 2 years, eight 3-month classes; from 2 to 14 years, twelve 1-year classes; from 14 to 18 years, one 4-year class. Results Cl, plotted against age, was fitted using an increasing function ($$y = a - be - cx$$). Mean 123I-OIH-Cl of 1,834 kidneys was 306+/-22 ml/min/1.73 m2 BSA. Mean 123I-OIH-Cl of the right and left kidneys was 307+/-23 and 305+/-22 ml/min/1.73 m2 BSA, respectively (p