MỐI TƯƠNG QUAN GIỮA KÍCH THƯỚC CƠ MU TRỰC TRÀNG VÀ MỨC ĐỘ SA TẠNG CHẬU NỮ TRÊN HÌNH ẢNH CỘNG HƯỞNG TỪ ĐỘNG SÀN CHẬU

Abstract

Objective: To analyze the correlation between the dimensions of the puborectalis muscle and the severity of pelvic organ prolapse (POP) according to pelvic compartments on dynamic pelvic floor magnetic resonance imaging (MRI). Materials and Methods: A cross-sectional descriptive study was conducted on 51 female patients diagnosed with POP who underwent dynamic pelvic floor MRI at Hanoi Medical University Hospital from June 2023 to May 2025. The dimensions of the puborectalis muscle, including thickness and length, were measured on high-resolution T2-weighted MRI sequences. The degree of organ prolapse was classified based on the distance of the pelvic organs from the pubococcygeal line (PCL) on straining-phase images and graded into three levels according to Yang’s classification. Data were analyzed using SPSS 20.0 software, and correlations between variables were assessed using Spearman’s correlation coefficient. Results: The mean age of patients was 62.1 ± 14.6 years, with 78.4% being postmenopausal. The rate of vaginal delivery was 88.2%. The mean thickness of the bilateral puborectalis muscle was 6.8 ± 1.7 mm. The mean length of the puborectalis muscle during straining was 76.6 ± 11.1 mm, significantly greater than at rest (60.9 ± 9.6 mm; p < 0.001). Spearman’s test revealed a positive correlation between puborectalis length during straining and the severity of rectocele, cystocele, uterine prolapse, and enterocele (r = 0.29 to 0.47; p < 0.05). Puborectalis length at rest was also positively correlated with cystocele severity (r = 0.41; p = 0.003). In contrast, puborectalis thickness showed a moderate negative correlation with the severity of uterine prolapse, cystocele, and enterocele (r = –0.37 to –0.41; p < 0.05). Conclusion: Dynamic pelvic floor MRI demonstrates a significant association between puborectalis muscle dimensions and the severity of pelvic organ prolapse, particularly in the middle and posterior compartments.