Clinical application of a fixed reference line in the ultrasound quantitative diagnosis of female pelvic organ prolapse

Objective This study explored using an improved ultrasound (US) for quantitative evaluation of the degree of pelvic organ prolapse(POP). Design A transluminal probe was used to standardize ultrasound imaging of pelvic floor organ displacements. A US reference line was fixed between the lower edge of the pubic symphysis and the central axis of the pubic symphysis at a 30°counterclockwise angle. Method Points Aa, Ba, C and Bp on pelvic organ prolapse quantification (POP-Q) were then compared with the points on pelvic floor ultrasound (PFUS). Results One hundred thirteen patients were included in the analysis of the standard US plane. Correlations were good in the anterior and middle compartments (PBN:Aa, ICC = 0.922; PBB:Ba, ICC = 0.923; and PC:C, ICC = 0.925), and Bland-Altman statistical maps corresponding to the average difference around the 30°horizontal line were close to 0. Correlations were poor in the posterior compartment (PRA:Bp, ICC = 0.444). However, eight (7.1%) cases of intestinal hernia and 21 (18.6%) cases of rectocele were diagnosed. Conclusions Introital PFUS using an intracavitary probe, which is gently placed at the introitus of the urethra and the vagina, may be accurately used to evaluate organ displacement. The application of a 30°horizontal line may improve the repeatability of the US diagnosis of POP.