[The stenotic-occlusive anatomy and pathology of the renal arteries. Their evaluation by magnetic resonance angiography].

Magnetic resonance angiography of the renal arteries was performed in 10 healthy subjects, 10 patients with renal artery stenosis and 2 patients with accessory renal artery (1 unilateral, 1 bilateral). All patients selected among 35 subjects with suspected renovascular hypertension had previously undergone digital subtraction angiography. Four patients were studied before and after percutaneous transluminal angioplasty. MRA was performed with time-of-flight technique, with 2D and 3D FISP and 2D FLASH gradient-echo sequences. Digital subtraction angiography demonstrated stenoses ranging 40% to 90% in 10 cases, 7 unilateral (1 transplanted kidney) and 3 bilateral. RA correctly depicted > 90% stenoses in 5 cases, between 50% and 90% stenoses in 2 cases and < 50% in 2 cases. Four stenoses were not properly graded (3 over-graded and 1 not visualized because distal to ostium). Diagnostic accuracy was 71% for unilateral stenoses and 66% for bilateral stenoses (overall accuracy 69.2%).