Detection of Concealed Uterine Prolapse in the Volume-Rendering Mode of 4-Dimensional Translabial Ultrasound: A Retrospective Observational Study

OBJECTIVES To assess the association between a widened vaginal canal on volume-rendered ultrasound (US) imaging with concealed uterine prolapse. METHODS This work was a retrospective study of 253 women who had an International Continence Society Pelvic Organ Prolapse Quantification System examination and translabial US examination. The anteroposterior diameter of the vaginal canal was measured in the rendered axial plane for all women. The widened vaginal canal was defined as an anteroposterior diameter above the 95th centile in women with normal uterine descent. The performance of the widened vaginal canal for prediction of clinical uterine prolapse was tested. RESULTS Valid data from 233 women were analyzed. A mean anteroposterior diameter of 5.6 mm (range, 2.3-10.5 mm; 95th percentile, 10 mm) was seen in 119 women with normal uterine descent. An eye-shaped vaginal canal with a mean anteroposterior diameter of 17.8 mm (range, 10.7-26.8 mm) was seen in 69 women with uterine prolapse. A widened vaginal canal was defined as an anteroposterior diameter of greater than 10 mm. Of 45 concealed uterine descents, 32 had a widened vaginal canal (ie, anteroposterior diameter > 10 mm), and 27 had clinical uterine prolapse. The κ test showed good agreement between physical and US findings (κ = 0.76; P