Intraobserver and interobserver reliability of the three-dimensional ultrasound imaging of female urethral sphincter...

The aim of the study was to assess the interobserver and intraobserver reliability of translabial 3D ultrasound imaging of the urethral sphincter in non-pregnant nulliparous asymptomatic women.

A study using a 3D translabial ultrasound on thirty-seven women was performed. Urethral sphincter parameters were measured by the same experienced clinician 2 weeks apart. Multiple axial cross-sectional areas at 1-mm distances were used to calculate urethral sphincter volumes. The same measurements were carried out by a second experienced clinician to assess the interobserver reliability.

We found an excellent intraobserver reliability (interclass correlation coefficient, ICC >0.8) and good interobserver reliability (ICC >0.6).

The described technique using multiple axial cross-sectional areas at set distances and a translabial approach is a reliable and accurate tool in the evaluation of the urethral sphincter. This should be used instead of mathematical formulas as the urethral sphincter is not a uniform geometrical sphere. The technique and values reported may help clinicians in the assessment of women with lower urinary tract disorders.