Figure 1. Renal cell carcinoma (histology: Robson stage I) in the lower part of the left kidney in a 57-year-old patient. Comparison of helical CT and fast MRI. (a) Helical CT in plain acquisition phase the tumour was slightly hypodense compared with the renal parenchyma. (b) Helical CT after application of contrast medium the renal cell carcinoma showed inhomogeneous enhancement in the tubulonephrographic phase. (c) Fast MRI in the axial T2 weighted ultrashort turbo spin echo (UTSE) sequence the normal renal parenchyma had intermediate signal intensity and the renal tumour showed predominantly hyperintense signal changes, indicating a cystic or necrotic component of the tumour. (d) Fast MRI after injection of contrast agent a similar enhancement pattern of the carcinoma was found in the axial T1 weighted UTSE sequence with fat suppression (SPIR) compared with the enhancement in helical CT. The renal cell carcinoma was correctly staged in both modalities (Robson stage I).