MAGNETIC-RESONANCE-IMAGING OF THE KIDNEY - EVALUATION OF NEW PULSE SEQUENCES AND COMPARISON OF CT IN DIFFERENTIAL-DIAGNOSIS OF SPACE-OCCUPYING LESIONS

Purpose: To evaluate new pulse sequences (turbo-spin echo [TSE] and tu rbo-field-echo [TFE] sequences) for study protocol optimisation and to assess the role of MRI in the differential diagnosis of renal tumours . Methods. In six volunteers MRI of the kidney was performed at 0.5 T using a conventional T-2 weighted spin-echo (SE) sequence (T-R/T-E 180 0/90 ms) and three different TSE sequences (T-R 1800-5000 ms, T-E 90-1 50 ms). Additionally CT and MRI was pel formed in 34 patients with 41 renal masses. Two readers evaluated both images regarding the differen tiation between malignant and benign masses. Results: The pilot study showed that the heavily T-2-weighted TSE sequence (T-R/T-E 5500/150 ms ) was superior to other sequences with regard to image quality and dif ferentiation of the corticomedullary junction. In the clinical study m alignant tumours were correctly classified with CT and MRI in 86.4% an d 95.5% of the cases, whereas the accuracy in the diagnosis of benign lesions of CT and MRI was 73.7% and 89.5%, respectively. Conclusion: U sing new puls sequences MRI is superior to CT in the differential diag nosis of renal tumours. MRI is superior to CT in the differentiation b etween complicated cysts and cystic or hypovascular renal cell carcino mas.