Evaluation of the Depth of Myometrial Invasion of Endometrial Carcinoma: Comparison of Orthogonal Pelvis-axial Contrast-enhanced and Uterus-axial Dynamic Contrast-enhanced MRI Protocols

RATIONALE AND OBJECTIVES: To compare the diagnostic performance of orthogonal pelvis-axial (OPA) contrast-enhanced (CE) and orthogonal uterus-axial (OUA) dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) protocols in assessing the depth of myometrial invasion (MI) of endometrial carcinoma (EC). MATERIALS AND METHODS: Preoperative MRI of 398 consecutive EC patients (197 patients with OPA CE-MRI protocol and 201 patients with OUA DCE-MRI protocol) was analyzed. Two radiologists independently interpreted the depth of MI, with postoperative histopathology as the reference standard. The chi-square test, Fisher's exact test, and receiver operating characteristic curve analysis were used for diagnostic performance comparison. RESULTS: OUA DCE-MRI showed a significantly larger area under the curve than OPA CE-MRI in detecting the presence of MI for radiologist 1 (0.71 versus 0.49, p 0.05). Compared to OPA CE-MRI, OUA DCE-MRI significantly improved the diagnostic accuracy of non-MI and superficial MI (radiologist 1: 45.5% versus 0 and 88.7% versus 86.4%, p = 0.045 and 0.567, respectively; radiologist 2: 45.5% versus 12.5% and 88.7% versus 78.8%, p = 0.177 and 0.027, respectively) and of EC with adenomyosis/submucous myomas, cornual tumor, and antero-posterior diameter ≤ 10 mm (radiologist 1: 86.4% versus 71.4%, 91.2% versus 67.7%, and 90.1% versus 81.1%, p = 0.048, 0.018, and 0.081, respectively; radiologist 2: 86.4% versus 64.3%, 88.2% versus 64.5%, and 87.0% versus 71.6%, p = 0.006, 0.023, and 0.019, respectively). CONCLUSION: The OUA DCE-MRI protocol was superior to the OPA CE-MRI protocol in assessing the depth of MI of EC.