Diagnostic Accuracy of 3D/4D Transvaginal Ultrasound Compared With MRI for Müllerian Uterine Anomalies: A Prospective Study Using Hysteroscopic Confirmation for Septate Uterus

Objective: To compare the diagnostic accuracy and concordance of three-dimensional/four-dimensional (3D/4D) ultrasonography and magnetic resonance imaging (MRI) in detecting Müllerian duct anomalies (MDAs) and to evaluate their impact on surgical decision-making. Methods: This prospective observational study included 32 patients who presented to the infertility or gynecology outpatient clinics at Gazi University Hospital between November 2016 and November 2017. All patients underwent both 3D/4D transvaginal ultrasonography (Voluson E6, GE Healthcare) and pelvic MRI (3T Verio, Siemens). Diagnoses were classified according to the American Society of Reproductive Medicine (ASRM, 1988) criteria. Concordance between the two imaging modalities was evaluated using the kappa (κ) statistic. Results: Of the 32 enrolled patients, 25 completed both imaging studies. Overall concordance between 3D/4D ultrasonography and MRI was 40% (κ = 0.266, p < 0.001), indicating low-to-moderate agreement. The most common diagnosis with 3D/4D ultrasonography was septate uterus (56%), compared with 20% by MRI. Among 13 patients who underwent surgery, 12 were correctly diagnosed as having septate uterus by 3D/4D ultrasonography (positive predictive value, 92.3%), while MRI correctly identified four (30.8%). Surgical decisions were based on 3D/4D ultrasonography in 69.2% of discordant cases and on MRI in 30.8%. Conclusion: Although MRI remains the reference standard for evaluating MDAs, 3D/4D ultrasonography demonstrated strong clinical value in guiding surgical management and offered advantages of accessibility, real-time assessment, and lower cost. We recommend that 3D/4D ultrasonography be performed by the operating gynecologist prior to surgical planning. Larger randomized studies are warranted to validate these findings.