Assessment of Urethral Elasticity by Shear Wave Elastography: A Novel Parameter Bridging a Gap Between Hypermobility and ISD in Female Stress Urinary Incontinence

Stress urinary incontinence (SUI) results from complex anatomical and functional interactions, including urethral mobility, muscle activity, and pelvic floor support. Despite advancements in imaging and electrophysiology, a comprehensive model remains elusive. This study employed shear wave elastography (SWE), incorporating sound touch elastography (STE) and sound touch quantification (STQ) with acoustic radiation force impulse (ARFI) technology, to assess urethral elasticity and bladder neck descent (BND) in women with SUI and continent controls. Between October 2024 and January 2025, 30 women (15 with SUI, 15 controls) underwent transperineal and intravaginal ultrasonography at IRCCS San Gerardo. Statistical analysis, conducted using JMP 17, revealed significantly greater BND in the SUI group (21.8 ± 7.8 mm vs. 10.5 ± 5 mm) and increased urethral stiffness (Young's modulus: middle urethra, 57.8 ± 15.6 kPa vs. 30.7 ± 6.4 kPa; <i>p</i> < 0.0001). Mean urethral pressure was the strongest predictor of SUI (<i>p</i> < 0.0001). Findings emphasize the role of urethral support and connective tissue integrity in continence. By demonstrating SWE's diagnostic utility, this study provides a foundation for personalized, evidence-based approaches to SUI assessment and management.