Diagnostic Accuracy of Transvaginal Ultrasonography Versus MRI in Early Detection of Adenomyosis

Background: Adenomyosis is a common gynecological condition characterized by the invasion of endometrial glands and stroma into the myometrium. Early and accurate diagnosis remains challenging due to overlapping symptomatology with other uterine pathologies. Both transvaginal ultrasonography (TVS) and magnetic resonance imaging (MRI) are widely utilized non-invasive diagnostic modalities, yet comparative evidence regarding their accuracy in early-stage adenomyosis detection remains limited. Methods: A prospective cross-sectional diagnostic accuracy study was conducted on 186 premenopausal women presenting with symptoms suggestive of adenomyosis. All participants underwent both TVS and pelvic MRI prior to hysterectomy. Histopathological analysis of hysterectomy specimens served as the definitive diagnostic reference. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy were calculated for both modalities. Results: Histopathology confirmed adenomyosis in 124 of 186 patients (66.7%). MRI demonstrated superior sensitivity (91.9% vs. 83.1%, p = 0.034), specificity (90.3% vs. 79.0%, p = 0.041), and overall diagnostic accuracy (91.4% vs. 81.7%, p = 0.012) compared to TVS. The area under the receiver operating characteristic curve (AUC) was significantly higher for MRI (0.941) than for TVS (0.862, p = 0.008). MRI showed particular superiority in detecting focal adenomyosis (sensitivity 89.5% vs. 68.4%, p = 0.018). Conclusion: MRI demonstrates significantly higher diagnostic accuracy than TVS in the early detection of adenomyosis, particularly for focal subtypes. However, TVS remains a valuable and accessible first-line screening tool.