Utility of 2D-ultrasound in pelvic floor muscle contraction and bladder neck mobility assessment in women with urinary incontinence

Assessment of pelvic floor muscle (PFM) contraction and bladder neck (BN) mobility in women with stress urinary incontinence (SUI) is essentially clinical. Ultrasound is increasingly used as a method for evaluating BN mobility and PFM contraction, but has not been standardized. The aim of this study was to review ultrasound technics and parameters that might be relevant for PFM contraction and BN mobility assessment in women with urinary incontinence (UI). We reviewed articles indexed in the MEDLINE database between 1988 and 2018 and selected articles which had a cohort of women with UI who had undergone functional 2D-ultrasound evaluation of PFM or BN mobility. Transperineal ultrasound provides a panoramic view of the pelvic organs without modifying the anatomical relationship between the urethra and surrounding structural landmarks. One of the measurements used to assess urethral mobility is bladder neck descent (BND), which has been shown to be extremely reliable. Measuring the anteroposterior diameter (APD) of the urogenital levator hiatus can also reliably quantify PFM contraction in women. The more recently developed technique of elastography could be an additional useful non-invasive method for measuring periurethral striated muscle stiffness. Several ultrasound parameters such as BND, anorectal angle displacement and periurethral stiffness as measured by elastography are relevant for investigating UI in women undertaking pelvic floor muscle training. Our hypothesis is that these ultrasound parameters can be correlated with urinary symptoms and clinical contraction assessment. They need to be validated for clinical use.