Magnetic resonance imaging of the kidney: evaluation of new pulse sequences and comparison of CT in differential diagnosis of space-occupying lesions

In six volunteers MRI of the kidney was performed at 0.5 T using a conventional T2 weighted spinecho (SE) sequence (TR/TE 1800/90 ms) and three different TSE sequences (TR 1800-5000 ms, TE 90-150 ms). Additionally CT and MRI was performed in 34 patients with 41 renal masses. Two readers evaluated both images regarding the differentiation between malignant and benign masses. The pilot study showed that the heavily T2-weighted TSE sequence (TR/TE 5500/150 ms) was superior to other sequences with regard to image quality and differentiation of the corticomedullary junction. In the clinical study malignant tumours were correctly classified with CT and MRI in 86.4% and 95.5% of the cases, whereas the accuracy in the diagnosis of benign lesions of CT and MRI was 73.7% and 89.5%, respecitvely. Using new puls sequences MRI is superior to CT in the differential diagnosis of renal tumours. MRI is superior to CT in the differentiation between complicated cysts and cystic or hypovascular renal cell carcinomas. (orig./MG)