Measuring Superficial Pelvic Floor Muscle Properties Using Transperineal Grayscale and Sonographic Elastography: A Feasibility Study

Objective: The objective was to test the feasibility and acceptability of a novel protocol to measure the properties of the superficial pelvic floor muscles (sPFMs) using grayscale ultrasonography (US), point shear-wave elastography (pSWE), and strain elastography (SE). Materials and Methods: This was an observational feasibility study. Feasibility was determined by assessing the number of US images acquired to measure sPFM properties using these tools. Thickness of the sPFMs was assessed using grayscale US, while stiffness and elasticity were measured using pSWE and SE. Results: Twenty-six women participated in this study. The US image acquisitions and analyses of sPFM properties were completed in 96% (25 of 26) of women. Several challenges related to the morphological characteristics of sPFM or the US assessment tools were encountered. When measuring the bulbospongiosus muscle, both the muscle and bulb of the clitoris were captured (they moved and contracted similarly and simultaneously). The small size of the ischiocavernosus and superficial transverse perineal muscles also made measuring stiffness challenging. Conclusion: Challenges were encountered when measuring the sPFMs using grayscale US, pSWE, and SE. Further studies are required to optimize the protocol to evaluate individual sPFM properties using these tools, with Duplex Doppler potentially valuable to distinguish between vascular and sPFM structures.