Evaluation of Suburethral Tissue Elasticity Using Strain Elastography in Women with Stress Urinary Incontinence

Objectives: Strain elastography (SE) is a non-invasive ultrasound-based technique for evaluating tissue elasticity. This study investigated whether SE can reproducibly detect differences in suburethral tissue stiffness between women with stress urinary incontinence (SUI) and continent controls. Methods: In this prospective cohort study, 40 women (20 with SUI, 20 continent controls) underwent introital two-dimensional (2D) ultrasound in the midsagittal plane at rest. SE was performed at three predefined suburethral regions of interest (ROIs): the internal urethral orifice (IUO), midurethra (MU), and external urethral orifice (EUO), with the adipose layer (AL) serving as reference tissue. Group comparisons and reproducibility analyses were conducted. Results: SE enabled reliable in vivo assessment of suburethral elasticity. Women with SUI demonstrated significantly higher tissue elasticity at all three urethral levels compared to controls. The MU level showed the highest diagnostic accuracy (AUC = 0.813; sensitivity = 0.65; specificity = 0.85). Measurement reproducibility was excellent, with intraclass correlation coefficients exceeding 0.95 across all ROIs. Conclusions: SE is a feasible, reproducible imaging modality for assessing suburethral biomechanics in women with SUI. It effectively distinguishes affected individuals from continent controls, particularly at the midurethral level. Standardized protocols and diagnostic thresholds are needed to facilitate clinical integration of SE in the evaluation and management of SUI.