[Echoencephalographic determination of normal values of the width of the third ventricle in children]

The maximum diameter of the third ventricle was ultrasonically determined on 769 children aged 3 to 10, of whom 401 were boys and 368, girls. The empirical range included values between 2.1 and 5.5 mm, the average value being 3.8 mm and the standard deviation, 0.57 mm. Limiting ranges bordering on pathological values are, for the time being, considered to be as follows: 4.5 mm in the third year of life; 5.0 mm in the fourth to fifth years of life; 5.5 mm in the sixth to seventh years of life; and 6.0 mm in the eighth to tenth years of life.