Diagnostic efficacy of diffusion-weighted MRI for pre-operative assessment of myometrial and cervical invasion and pelvic lymph node metastasis in endometrial carcinoma

Introduction: To determine the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) for the pre-operative assessment of patients with endometrial carcinoma and to assess myometrial and cervical invasion as well as pelvic lymph node metastasis. Methods: Fifty-eight women who underwent surgery for histopathologically confirmed endometrial carcinoma were included in the current study. Prior to surgery, patients were evaluated using pelvic DW-MRI and gadolinium-enhanced T1-weighted imaging (Gd-T1WI). Gd-T1WI was evaluated together with T2-weighted images. DW-MR images were obtained in the axial plane using echo-planar spin-echo pulse sequences with different b factors. Endometrial carcinomas were observed as areas of increased intensity on DW-MRI images, and their intensity was compared with the surrounding hypo-intense myometrium. Pre-operative DW-MRI and Gd-T1WI results were compared with post-operative histopathological findings that served as reference standards. Results: The sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and diagnostic accuracy of DW-MRI for differentiation between superficial myometrial invasion and deep myometrial invasion were 85%, 89%, 81%, 92% and 88%, respectively. The sensitivity, specificity and diagnostic accuracy rates were 82%, 91% and 89.6% for cervical invasion and 100%, 96% and 96.5% for pelvic lymph node metastasis, respectively. The sensitivity, specificity, PPV and NPV, and diagnostic accuracy of Gd-T1WI for differentiation between superficial myometrial invasion and deep myometrial invasion were 85%, 81.5%, 71%, 91% and 83%, respectively. The sensitivity, specificity and diagnostic accuracy were 73%, 89% and 86% for cervical invasion, respectively. Conclusions: These findings suggest that DW-MRI may be a good diagnostic tool with high sensitivity and specificity for assessing myometrial invasion and detecting tumour extension. We suggest that DW-MRI should be considered as a routine part of the pre-operative pelvic MRI in all patients with endometrial carcinoma.