[Magnetic resonance angiography with TOF-TONE tridimensional sequences in the study of steno-occlusive diseases of the renal arteries. Comparison with digital angiography].

The authors examined 32 patients (68 renal arteries in all) with suspected renovascular hypertension with MRA (3D TOF-TONE sequences) and DSA. MRA visualization of the renal vessels was considered good in 96.8%, 91.6%, 76.6% and 16.6% of cases for the ostium, the proximal third, the distal third and the hilum, respectively. MRA correctly assessed the 4 occlusions in our series and 19/20 atherosclerotic stenoses, all in proximal site. In proximal stenosis detection, MRA had 100% sensitivity and 98% specificity in atherosclerotic sclerosis-occlusion grading considering a 50% caliber reduction as the cut-off value. The two techniques were in agreement in 68% of cases; MRA overestimated stenosis grade in 25% of cases. The 3D TOF-TONE sequence is a reliable diagnostic tool in the study of the proximal tract of the renal arteries, but its major limitation remains in distal tract studies. Nevertheless, this technique has elective indications in a selected group of patients, namely the elderly with hypertension and impaired renal function.