Sonografische Harnblasenvolumetrie bei Kindern: vergleichende Beurteilung von konventioneller B-Bild-Sonografie und automatisierter Volumetrie mit einem sonografischen Handgerät ohne Bildgebung

PURPOSE: Evaluation of a handheld sonographic tool for the automatic estimation of bladder volume in comparison with conventional sonography in children under clinical conditions. MATERIALS AND METHODS: 139 children (age: 30 days - 17 years) were examined with both conventional sonography and the handheld scanning device BVI 6200. For conventional sonography two different formulas were used to calculate the bladder volume. RESULTS: The mean error of the three methods was 22.4 % for the handheld tool, 37.4 % for the most frequently used prolate ellipsoid formula in conventional sonography, and 23 % for an alternative formula recommended in the literature. In 19 cases the first automated sonography scan showed a false-negative result (empty bladder), while the automatically calculated volumes were between 17 and 60 ml in 5 cases of empty bladder. In one of these cases a megaureter and in another an ovarian cyst were detected by conventional ultrasound. CONCLUSION: Since pathologies are not visualized and can be misinterpreted as a nonempty bladder, the automated method should only be used in follow-up studies. In every case automated volumetry should be performed repeatedly to avoid false-negative results.