Strengths and limitations
Maintaining normal anatomical appearances in situ is a prerequisite for well-functioning pelvic organs. Pelvic organ prolapse (POP) mostly occurs in the upper two-thirds of the vagina. Although the vaginal shape and dimensions have been previously studied16, the method used to evaluate this part of the vagina in situ is seldom reported but could be of great clinical value. This study is the first to attempt to introduce a line for an in situ evaluation of the upper two-thirds of the vagina on MRI.
Limitations exist in our study. First, this study adopted a retrospective cross-sectional design; the clinical examinations were not always performed by experienced physicians familiar with POP quantification. Second, not all patients had a transabdominal or laparoscopic surgical record, which was important for identifying dense, extensive adhesions between the pelvic and abdominal walls that may potentially change the direction of the vagina. Finally, MRI was conducted in the supine position in all patients in this study; thus, the results may not reflect pelvic organ positions in the standing position17.