Diagnostic Accuracy of Multidetector-row Computed Tomography Study in Assessment of Mesorectal Fascia Invasion for Staging of Rectal Cancer Patients in Comparison with Magnetic Resonance Imaging

A total of 79 patients with biopsy proven primary adenocarcinoma of the rectum who were referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed both on a 256 row scanner (ICT, Philips) and on 16 row scanner (Brilliance 16P, Philips) with the following acquisition parameters: tube voltage 120 KV and tube current 150-300 mAs (depending on patient's weight). Multiplanar CT reconstructions were performed and the imaging data were reviewed as axial images and then as MPR images: coronal, sagittal, perpendicular and parallel along with rectal tumour axis. The MRF was readily identified in all patients as a thin, isodense to muscle, curvilinear envelope adjacent to the rectum and the mesorectal fat. The MR study, performed on 1.5 T with a dedicated phased array multicoil, included multiplanar T2 weighted sequences and axial T1 weighted sequences. Axial and MPR CT images were then compared to MRI imaging in order to assess the involvement of MRF. Diagnostic accuracy of both modalities was compared and statistically analyzed.