[Sonographic determination of residual urine]

A method to determine residual urine volume by ultrasonotomography has been developed. In 206 patients the greatest horizontal and the greatest sagittal area of the urinary bladder were measured using a B-Mode real time scanner and the volume of the bladder was calculated from these two parameters. Then the bladder was emptied with a catheter and the determined volume was compared with the calculated volume. Applying the statistical method of multiple regression analysis a nomogram was computed for direct reading of the calculated residual urine volume. Using this ultrasonic method the bladder volume determination is highly reliable and due to its advantages (e.g. no risk of infection and urethral injury, quick, simple and inexpensive) it has replaced the catheter method for assessing residual urine volume at our institution.