Ultrasound Features of Adenomyosis in Women with Secondary Dysmenorrhea

Background: Adenomyosis is a benign uterine disorder frequently associated with secondary dysmenorrhea. The advent of the Morphological Uterus Sonographic Assessment (MUSA) criteria has standardized sonographic diagnosis, yet the relationship between ultrasound features and symptom severity remains insufficiently defined. The aim of this study was to evaluate the different sonographic features of adenomyosis based on transvaginal ultrasound (TVUS) and correlate type and degree of adenomyosis to severity of menstrual pain. Methods: A prospective cohort study was conducted at Zagazig University Hospitals between November 2024 and November 2025, including 42 premenopausal women with sonographic features of adenomyosis. Participants were classified into mild, moderate, and severe dysmenorrhea groups based on the Numerical Rating Scale (NRS). Ultrasound findings were assessed according to the 2022 revised MUSA criteria, and disease severity was quantified using a modified MUSA scoring system. Results: Both direct and indirect MUSA signs showed significant correlations with pain severity. The presence of myometrial cysts (p=0.004), echogenic subendometrial lines (p=0.002), and irregular junctional zone (p=0.002) were the most discriminatory features. Disease extent (>50%) demonstrated the strongest association with severe dysmenorrhea (p=0.001) and emerged as the only independent predictor in multivariate analysis (adjusted OR=6.87, p= 0.004). The total MUSA score correlated strongly with pain severity (r=0.524, p=0.001). ROC analysis confirmed disease extent (AUC=0.847) and total MUSA score (AUC=0.798) as reliable predictors of severe symptoms. Conclusion: Ultrasound evaluation based on MUSA criteria provides valuable quantitative parameters for predicting dysmenorrhea severity in adenomyosis.