Doppler ultrasound in determination renal blood flow in healthy children

Purpose: To determine the normal values of renal volume perfusion in healthy children.

Material and methods: 60 children without renal disease at the age of 6 years to 17 years 11 months were examined by means of an ultrasonic diagnostic apparatus “Medison” (convex and linear high-frequency transducers with frequencies up to 14 MHz). The marks of renal arteries were set with a color Doppler for each child, and then their diameters were measured in grayscale. The time-averaged mean velocity of blood flow was determined with a pulse wave Doppler. Both figures were used to renal blood flow calculation. This value was related to the value of body surface area (BSA) calculated for each child.

All the children were divided into 4 groups according to age: from 6 years to 8 years 11 months, from 9 years to 11 years 11 months, from 12 years to 14 years 11 months, from 15 years to 17 years, 11 months.

Data were tested with Student t-test to the mean value of volumetric renal perfusion determination. The Mann-Whitney-Wilcoxon rank sum W test was used to test differences between the age groups. The results of renal blood flow of both kidneys were compared using the same method.

Results: The average value of volumetric renal perfusion related to BSA for the right kidney was found to be 264.98 mL/min * m², for the left – 320.78 mL/min * m². There was no statistically significant difference between the age groups (p > 0.05). Comparison of both kidneys revealed no significant differences between left and right kidneys renal blood flow.

Conclusion: Volumetric perfusion related to the body surface area is constant throughout childhood. Thus, this parameter can be used to valuation kidney function in healthy children and in children with renal disease.