Variations in Female Pelvic Anatomy via MRI: Retrospective, Nonrandomized Study

Background/Objectives: Pelvic floor disorders affect up to 30% of adult females in the United States. Misdiagnosis occurs in nearly 45% to 90% of cases. Standardized pelvic anatomical measurements could improve diagnostic accuracy and treatment planning. We aimed to evaluate pelvic anatomical variations using magnetic resonance imaging (MRI).Methods: We analyzed MRI pelvic measurements from 250 women aged 20-90 years. Exclusion criteria included prior pelvic surgery (except hysterectomy), pelvic cancer, and use of alternative imaging modalities. Key measurements included anterior vaginal wall thickness (AVWT), bladder wall thickness (BWT), vaginal epithelium to bladder urothelium (VWBU), urethral length (UL), and inter-ureteral distances. Results: AVWT correlated positively with VWBU (rs = 0.542, p < 0.001) and UL (rs = 0.168, p = 0.036). Decreasing VWBU was associated with reduced BWT (rs = 0.233, p = 0.001). Women with incontinence exhibited significantly thinner BWT (2.3 ± 0.6 mm) compared to those without (3.2 ± 0.9 mm, p = 0.041). AVWT declined with age (p < 0.001), and UL to the distal urethral sphincter was shortest among Caucasian women (p = 0.016). The tissue thickness between vaginal epithelium and bladder urothelium was 9.7 mm. AVWT was greater in those < 45 years of age (4.3 mm ± 1.5) compared to those >65 years (3.5 mm ± 1.4). Conclusions: MRI-derived BWT measurements may serve as a noninvasive marker for incontinence, while AVWT and VWBU may offer insights into pelvic support. Further multicenter studies are needed to standardize imaging parameters and validate predictive anatomical markers.