Ultrasound assessment of residual urine in children.

Ultrasound has been used to assess residual urine in children and found to have considerable advantages over other methods. Using a B-mode scan in the sagittal plane the presence or absence of residual urine can be confidently determined. Quantitative measurements of volume are subject to considerable error but semi-quantitative information in individual cases can be obtained by comparison of records made at subsequent examinations. More accurate quantitative values might be achieved by constructing an individual calibration curve. The advantages of ultrasound for assessing residual urine are that it is simple, quick, harmless and non-invasive. Because of these features the examination can be readily repeated, is suitable for out-patient use and is acceptable to children.