Field-of-View Optimized and Constrained Undistorted Single-Shot Study of Diffusion-Weighted Imaging and Intravoxel...

The female reproductive system undergoes hormone-driven cyclical changes during the menstrual cycle and further alterations after menopause. However, the impact of these changes on imaging parameters remains unclear. This study aimed to compare diffusion-weighted imaging and intravoxel incoherent motion (DWI-IVIM) parameters of the uterus and cervix in women of childbearing age across different menstrual phases and in postmenopausal women.

This prospective study was conducted from January 2022 to January 2024. Routine pelvic MRI and DWI-IVIM scans were performed in women of childbearing age during the menstrual phase (MP), follicular phase (FP), and luteal phase (LP), and at any time in postmenopausal women. Intraclass correlation coefficients (ICCs) were used to assess intra- and inter-observer repeatability of DWI-IVIM parameters.

Repeatability analysis demonstrated excellent intra- and inter-observer agreement for ADC, good agreement for D and f, and poor agreement for D* values. Compared with postmenopausal women, endometrial ADC, D, and D* values were significantly lower during the MP (ADC: p < 0.001; D: p = 0.003; D*: p = 0.007), while f values exhibited a non-significant downward trend (p = 0.09). No significant differences in DWI-IVIM parameters were observed in the uterine junctional zone across menstrual phases. In the myometrium, ADC values were significantly higher during the FP compared with postmenopause (p = 0.006). Cervical ADC, D, and f values were significantly higher across all menstrual phases than in postmenopausal women (ADC: MP/FP/LP p < 0.001; D: MP/FP p < 0.001, LP p = 0.02; f: MP/FP p < 0.001, LP p = 0.003), whereas D* values were significantly lower during all menstrual phases compared with postmenopause (MP/FP p < 0.001, LP p = 0.005).

These findings indicate that DWI-IVIM parameters are sensitive to physiological variations in the uterus and cervix associated with menstrual cycles and menopausal status, highlighting the importance of considering hormonal and age-related factors in clinical interpretation of functional MRI results for the female reproductive system.

DWI-IVIM parameters can detect physiological differences in the uterus and cervix between menstrual phases and postmenopause. These findings underscore the importance of considering hormonal and physiological variability when interpreting imaging studies of the female reproductive system. Further research is warranted to explore the diagnostic implications of these parameters.