Perineal ultrasound: determination of reliable examination procedures.

This is a report on the fundamentals of perineal ultrasound examination for female incontinence. The measurement method described here enabled us to determine the position of the bladder neck, the size of the retrovesical angle beta and the occurrence of funnelling. In four different investigations, each involving at least 30 patients, we investigated the influence of examination position, bladder filling volume and pressure of the ultrasound probe against the perineum on these measurements and analyzed the difference between coughing and the Valsalva maneuver. The results showed that when the patient is standing, the bladder neck is lower than when the patient is supine. We also observed that excessive pressure on the ultrasound probe displaces the bladder neck cranially and can squeeze the urethra. Increasing the bladder filling volume does not affect the measurement values, but funnelling can be seen better with higher bladder volumes. The best overall image quality was obtained at 300 ml. A comparison between coughing and the Valsalva maneuver showed that during coughing, the bladder neck descends less and remains closer to the symphysis than with the Valsalva maneuver.