Endometrial cancer with cervical stromal invasion: diagnostic accuracy of diffusion-weighted and dynamic contrast enhanced MR imaging at 3T

Objectives: To compare the diagnostic accuracy of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging for detecting cervical stromal invasion in endometrial cancer. Methods: Eighty-three consecutive women with endometrial cancer underwent preoperative evaluation in a 3-T unit, including T2-weighted, DW (b = 0 and 1000 s/mm²), and DCE MR imaging. Two radiologists independently assessed presence of cervical stromal invasion, with histopathological reference as gold standard. Results: For assessing cervical stromal invasion, the diagnostic accuracy, sensitivity, and specificity, respectively for Reader 1/Reader 2, were as follows: DW MR imaging— 95.2 %/91.6 %, 91.7 %/100 %, and 95.8 %/90.1 %; DCE MR imaging— 91.6 %/88 %, 58.3 %/50 %, and 97.2 %/94.4 %. The diagnostic performance of DW MR imaging (Reader 1: areas under the receiver operating characteristic curve (AUC) = 0.98; Reader 2: AUC = 0.97) was significantly higher than that of DCE MR imaging (p = 0.009 for Reader 2) or T2-weighted MR imaging (Reader 1: p = 0.006; Reader 2: p = 0.013). Patients with cervical stromal invasion showed a significantly greater canal width (p < 0.0001) and myometrial invasion extent (p = 0.006). Conclusions: DW MR imaging has superior diagnostic performance compared with DCE MR imaging in the detection of cervical stromal invasion. Key Points: • DWI demonstrates a higher accuracy than DCE in detecting cervical stromal invasion. • Tumour ADC values are similar between patients without or with cervical invasion. • Canal widening causes false-negativity on DCE and T2W but not on DWI.