High-resolution three-dimensional endovaginal ultrasonography in the assessment of pelvic floor anatomy: a preliminary study.

Introduction and hypothesis: Our aim was to evaluate the morphological characteristics of the female pelvic floor that may be further elucidated with three-dimensional endovaginal ultrasonography (3D-EVUS).

Methods: A consecutive series of 20 nulliparous females underwent 3D-EVUS. Measurements were determined according to pre-established criteria. Descriptive statistics and Spearman's correlation test were performed.

Results: The levator hiatus (LH) was measured in the oblique plane parallel to the pubovisceral muscle. A positive correlation was found between LH area and age (p = 0.03). The anteroposterior diameter of the urogenital hiatus, measured in the axial plane tilted from the symphysis pubis to the ischiopubic rami, correlated with LH area (p = 0.008). No urethral rotations were observed in the coronal plane. Significant correlations were found among urethral parameters. Mean anal sphincter measurements were comparable to previously reported magnetic resonance imaging and ultrasound measurements.

Conclusions: 3D-EVUS allows measurements of key pelvic floor structures in planes that cannot be determined by conventional imaging modalities.