THE PELVIS AFTER SURGERY AND RADIOCHEMOTHERAPY FOR RECTAL-CANCER STUDIED WITH GD-DTPA-ENHANCED FAST DYNAMIC MR-IMAGING

The aim of this work was to study the gadolinium-enhancement of malign ant and benign pathology in the pelvis after surgery for rectal cancer . Thirty patients with either local recurrence (n = 17) or benign chan ges related to treatment for rectal cancer (n = 13) were studied with pelvic MR imaging. T2-weighted fast spin-echo as well as T1-weighted s pinor gradient-echo imaging before and after intravenous contrast was performed and referred to as contrast-enhanced MRI(CEMRI). In addition , between the pre-and postcontrast images, dynamic contrast-enhanced M RI (DCEMRI) was performed using a single-slice, multi-phase, contrast- enhanced T1-weighted fast spoiled gradient-echo sequence. The time bet ween the start of contrast injection to the beginning of enhancement, the duration and rate of enhancement as well as enhancement amplitude were recorded. The data were compared with the clinical diagnosis acco rding to biopsy in 8 patients and surgery in 6 patients. In the remain ing 16 patients, the clinical diagnosis was obtained by clinical or ra diological follow-up. DCEMRI did not improve the diagnostic informatio n compared with CEMRI. None of the examined parameters were found to h elp discriminating malignant from benign changes. Characterisation of lesions in the pelvis after rectal cancer surgery was not improved by a dynamic gadolinium-enhanced sequence.