The role of magnetic resonance imaging and magnetic resonance diffusion weighted image in preoperative staging of rectal cancer in comparison to postoperative histopathology

Abstract

Background: With outstanding soft tissue contrast, functional imaging capabilities, and multiplanar capacity, high-resolution phased-array magnetic resonance imaging MRI is considered as a basic imaging modality for preoperative local staging of rectal cancer. And so MRI fills a void in clinical practice by allowing for precise local staging of rectal cancer prior to treatment decisions. The diffusion-weighted image used as enhancing utility for MRI in patients with rectal cancer. Objectives: The aim of work was to assess the role of MRI imaging including the (diffusion weighted imaging DWI and Apparent diffusion coefficient ADC map) in preoperative rectal cancer staging, in comparison to post-operative histopathology. Patients and methods: A total of 50 patients were included in the study, presented to South Valley University hospital and underwent MRI examination in MRI unit at South Valley University hospital. Results: Regarding the circumferential resection margin (CRM) infiltration, MRI diagnosed CRM involvement in 15 cases while rest 35 cases showing free CRM. From these positive cases only 13 were truly positive with histopathology, other two cases proved to be positive with histopathology not diagnosed by MRI. MRI showed MRF infiltration in only 18 cases. Histopathological assessment showed that MRF infiltration in only 15 cases and the rest 35 cases showing free MRF (agreement 83.3%). Conclusion: The results of this study demonstrate that preoperative MRI has a great value in achieving the best treatment strategy through accurate staging of rectal cancer, prediction of negative CRMs and involvement of the perirectal and pelvic LNs.