[Normal values of urine stream velocity in boys]

Apart from the uroflowmetry the measurement of the speed of the urinary stream proved as second suitable non-invasive parameter for the clarification of subvesical obstructions in boys. Above all the combination of the two measuring methods with the help of the urinary stream speed-uroflow-diagram rendered possible a good differentiation of different forms of obstruction (proximal vs distal). Since up to now only few data existed for children, the attempt was made to gain normal values of the speed of the urinary stream of boys. In 37 boys in whom a subvesical obstruction could be excluded radiologically as well as with the help of combined urodynamic methods combined measurements of speed and flow were performed. The speed values were between 235 and 325 cm/s, the uroflow values between 12.5 and 30 ml/s. The data obtained were written down into a V/Q diagram and in this way a normal region could be restricted so far that by this means the delimitation of pathological V/Q-values is rendered possible and thus the classification of subvesical obstructions in boys is facilitated by non-invasive methods.