Role of MRI in diagnosis and preoperative staging of rectal carcinoma

Abstract

Background and objectives High-resolution phased-array MRI is recommended as a standard imaging modality for preoperative local staging of rectal cancer with excellent soft tissue contrast, functional imaging ability, and multiplanar capability. With these inherent proprieties, MRI fills a gap in clinical practice and helps accurate local staging of rectal cancer before management decisions. Invention of diffusion-weighted image has also improved utility of MRI in patients with rectal cancer. Addition of diffusion-weighted image to T2-weighted imaging improved accuracy of rectal cancer detection and can facilitate lymph node detection (6% more nodes) than T2-weighted imaging alone. Aim of the work The aim of this study is to detect the role of MRI in diagnosis and preoperative staging of rectal carcinoma. Patients and methods This study was conducted on 40 patients with rectal neoplasms and/or highly suspected clinically to have rectal neoplasms who were referred from oncology medicine department to radiodiagnosis department for MRI preoperative evaluation and staging of rectal neoplasm. A prospective study was conducted using randomized controlled trials. Informed consent from a parent or guardian was obtained. Results Phased array surface coil MRI has proved high agreement with postoperative histopathological examination, reaching 100% in T staging and 90% in N stages and 100% in detection of circumferential resection margin involvement, which match with many previous similar studies. Conclusion Our study results demonstrate that high-resolution MRI has a pivotal role in accurate staging of rectal cancer, prediction of negative circumferential resection margin and involvement of the perirectal and pelvic lymph nodes. Thus, we conclude MRI has a golden standard value in the establishment of the best treatment strategy.

Keywords

• apparent diffusion coefficient
• diffusion-weighted image
• magnetic resonance imaging
• rectal neoplasm