Trans-abdominal ultrasound shear wave elastographyfor quantitative assessment of female bladder neck elasticity.

Introduction and Hypothesis: Disorders of micturition result from a wide variety of conditions and evaluation often involves multiple diagnostic modalities. However, the sensitivity and specificity of these techniques are highly variable and may not always yield a diagnosis. Novel imaging techniques such as ultrasound shear wave elastography may help to improve diagnostic accuracy.
Methods: Continent women were recruited from outpatient gynecology offices from a tertiary medical system. Participants underwent ultrasound evaluation with measurement of the shear wave velocity (SWV) of the bladder neck (BN). SWV was used to determine the Young's modulus of the bladder neck. The median bladder neck stiffness was calculated and univariate and step-wise and backward multivariate logistic regression analyses were used to identify significant patient characteristics associated with bladder neck stiffness above or below the median.
Results: Fifty-seven women underwent SWE of the bladder; 12 were excluded, and 45 were included in the analysis. The median bladder neck stiffness of the study population was 22 (17.1-28.2) kPa. Age greater than 45 years was associated with a bladder neck stiffness above the median, OR 8.39, p < 0.001. Having no vaginal deliveries was also associated with a bladder neck stiffness greater than 22 kPa, unadjusted OR 4.76 (95 % CI 1.41-20.0, p = 0.012). Bladder volume and bladder neck thickness were not significantly associated with bladder neck stiffness above or below the median.
Conclusion: Trans-abdominal shear wave elastography can be used to quantitatively assess bladder neck stiffness. This technique may potentially be useful for evaluating chronic urinary retention.