[Ultrasonic kidney size measurement. 1. In infants and children].

Ultrasonography in a sector scanner at real time was performed on the normal kidneys of 126 males and 101 females up to 12 years of age including infants. The growth of the kidneys was well correlated with the age, height and body weight, but the following findings of the kidney length were obtained when the male and female kidneys were measured in a comprehensive manner. 1) y (mm) = 2.987 X age + 55.029 with 0.864 correlation coefficient and less than 1% risk rate showed a positive correlation with the age. 2) y (mm) = 0.407 X height + 28.045 with 0.879 correlation coefficient and less than 1% risk rate showed a positive correlation with the height. 3) y (mm) = 0.949 X body weight + 50.904 with 0.878 correlation coefficient and less than 1% risk rate showed a positive correlation with the body weight. No difference was recognized between both sexes and the right and left kidneys of infants and school students in their kidney length and thickness.