Staging of renal cell carcinomas via MRI and CT - A prospective histologically controlled study

Purpose: To evaluate the accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in staging renal carcinoma. Material and methods: 33 renal carcinomas were preoperatively examined for tumour staging by CT and MR imaging and correlated with histopathological staging. CT imaging was performed at first as a non-contrast scan. Finally incremental images (10 mm) after intravenous contrast injection were obtained. In MR imaging we performed a transversal T-1-weighted GE sequence (112/5) with and without CDTPA, a transversal fat-suppressed double-echo sequence (3900/22/90), a coronal T-1-weighted GE sequence with and without GDTPA and a coronal T-2-weighted TSE sequence (2800/128), In addition, dynamic T-1-weighted GE imaging after GDTPA injection as well as TOF angiography in coronal direction were performed. Finally CT and MRI findings were correlated with surgical and histopathological staging results. Results: CT and MRI staging was correct in 27 and 28 of 33 tumours. Sensitivity and specificity for tumour stage T3 b to T4 was for MIRI and CT 88.9% and 95.8%. With MRI 4 out of 7 thrombi were correctly diagnosed with high accuracy, but via CT none. Conclusion: In early stage renal carcinoma CT and MR imaging yielded similar staging accuracies. In advanced renal carcinoma MRI was superior to CT imaging, especially in diagnosing tumour thrombus. Consequently the extent of tumour thrombus may be assessed by MRI which may therefore replace conventional cavography.