Dynamic pelvic floor ultrasound for lower urinary tract symptoms in children--initial report on normative values.
PURPOSE
Lower urinary tract symptoms (LUTS) are common in children. The aim of this study was to determine normal values for pelvic floor movement in asymptomatic controls to allow comparison with symptomatic children with dysfunctional voiding (DV) in the next phase of the study.


MATERIAL AND METHODS
One hundred children between the ages of 5-17 years were recruited prospectively as controls. All were asked to perform a voluntary pelvic floor contraction manoeuvre with a full bladder. All scans were performed on a Vivid I GE ultrasound machine with a 4-9 MHz curvilinear probe. M Mode was used to determine the direction of pelvic floor (levator plate-LP) movement, the distance in cms and the endurance in seconds. Each measurement was taken 3 times.


RESULTS
Six children were unable to understand and perform the manoeuvre and were excluded. The median age was 10 years (range 4-17). The median LP movement was 0.3 cm (range 0.1-1.6) and cranial in 86/94 (91%). The median endurance time was 5.8 s (range 2.3-15.5). For the (n = 59) younger children aged 4-11, the 95% normal reference range for LP movement was 0.1 cm-1.4 cm and for endurance was 2.5-13.5 s. For the (n = 33) older children aged 12-17, the 95% normal reference range for LP movement was 0.2 cm-1.2 cm and for endurance was 2.3-15.5 s. There was a significant correlation (Pearson r = 0.39, P = 0.001) between average LP movement and endurance.


CONCLUSIONS
This study gives the normal reference ranges for the variables measured. A further study is currently underway examining the same variables in children with dysfunctional voiding (DV) and comparing these with the reference range.