Ultrasound assessment of the perineal body: A scoping review

The perineal body (PB) is a pyramidal fibromuscular structure located in the anterior part of the perineum, between the rectum and the vagina. It serves as a crucial component of the pelvic floor support system, particularly at levels II and III. Current understanding of pelvic floor anatomy is largely derived from cadaveric dissection and magnetic resonance imaging (MRI). However, ultrasound offers a promising alternative due to its ability to provide dynamic, non-invasive assessment, along with broad availability and cost-effectiveness. Importantly, ultrasound has the potential to reveal new insights into the anatomy of the perineal body and its functional role in both the static and dynamic support of the female pelvic floor.

This review followed the PRISMA-ScR guidelines. A comprehensive literature search was conducted in MEDLINE, Scopus, Web of Science, and grey literature sources. Eligible studies included English-language publications involving ultrasound visualization or measurement of the PB in women. Data extraction and screening were conducted independently by two reviewers, with discrepancies resolved through consensus. Data extraction encompassed a comprehensive set of variables, including study number, study design, total sample size, subgroup sample sizes, ultrasound approach, probe type, parameters measured, imaging position, and main findings.

A total of 22 studies were included in the scoping review, with publications ranging from 1997 to 2025. The majority of studies were observational, and sample sizes varied from 22 to 1340 (mean 154) participants. In most studies published before 2012, endoanal ultrasound (EAUS) was the most commonly used modality. With advances in transvaginal ultrasound technology and the introduction of transperineal ultrasound, detecting and measuring the perineal body has become more accessible and precise. The perineal body can now be measured in three dimensions-depth, height, and width-rather than relying solely on the traditional measurement of perineal body thickness.

In conclusion, the perineal body is an important anatomical structure that can be clearly visualized and measured using ultrasound; however, significant heterogeneity in imaging approaches, probe types, and anatomical definitions underscores the need for standardized methodologies to improve reproducibility and support future clinical application in the diagnosis and management of pelvic organ prolapse.