The Value of 2D MRI and 3D MRI Sequences in Preoperative Staging of Rectal Cancer

Objective: To evaluate the accuracy of the preoperative local-regional staging of the rectal cancer by a two-dimensional (2D) T2-weighted TSE sequence and a three-dimensional (3D VISTA) T2-weighted turbo spin-echo (TSE) magnetic resonance (MR) sequence. Materials and Methods: This retrospective study was conducted of 33 patients who diagnosed rectal cancer pathologically from January to April in 2016. Two radiologists independently assessed the radiologic images for T and N staging. All patients were performed with both 2D-T2WI MRI and 3D VISTA MRI of the rectum by Philips 3.0T MR imager. The accuracy and consistence with pathological results of TN staging using 2D and 3D sequences were calculated using SPSS 23. Results: in 33 cases, T staging accuracy values of 2D and 3D VISTA data were 70% and 85%, respectively (Kappa value were 0.576 and 0.790) for reviewer 1 (P=0.274) and 73% and 82% (Kappa value were 0.618 and 0.746) for reviewer 2 (P=0.454), The agreement of VISTA T sequences between 3D staging and pathologic results was excellent and better than that of 2D sequences; N category lesion staging accuracy values for 2D and 3D VISTA data were 58% and 70%, respectively (Kappa value were 0.252 and 0.407) for reviewer 1 (P=0.182) and 58% and 67% (Kappa value were 0.267 and 0.376) for reviewer 2 (P=0.218). The agreement of N staging 2D and VISTA 3D staging with pathological results were both poor agreement. Conclusion: Preoperative staging with conventional 2D MR imaging sequence and 3D VISTA T2-weighted imaging protocols for rectal cancer patients showed no significant differences in accuracy of TN staging. However, compared to 2D sequence, 3D VISTA sequence has its advantages in preoperative MR staging.