The standard renal volume of Japanese boys and girls determined by three-dimensional ultrasonography.

We calculated the volume of the kidney in 442 kidneys in 221 normal children (15 neonates, 45 infants, 82 boys and 79 girls between 1 and 15 years of age) by using three-dimensional ultrasonography. The standard curves of the renal volume by height and age were determined. No differences in the renal volumes were observed between boys and girls from 1 to 14 years of age, whereas the difference between volume in boys and girls 15 years of age was significant; the boys had larger kidneys. A significant correlation between height and the volume of the right kidney (r = 0.756, P < 0.0001), and between height and the volume of the left kidney (r = 0.791, P < 0.0001) was observed. In addition, a significant correlation was found between the renal volume and the standard renal weight in male and female Japanese children. The results provide a new standard for renal volume in Japanese children. It is considered that this standard curve might be useful in a clinical setting, as a reference for evaluating patients with renal diseases that may affect the volume of the kidneys.