Multidetector-row CT of renal arteries: review of the performances in normo- and hypertensive patients.

OBJECTIVE: To justify and illustrate the advantages of multidetector-row CT (MDCT) as probably the most effective method for imaging of renal arteries and to debate the question of multiple renal arteries.

METHODS AND MATERIAL: The renal arteries of 158 hypertensive patients were investigated with 8-row and 16-row MDCT using a highly standardized protocol; the results were compared with those obtained in a group of 112 normotensive patients.

RESULTS: MDCT of the renal arteries was found technically safely interpretable in 97.4% of cases. Fibromuscular dysplasia was found in 7/156 hypertensive patients (4.66%) concerning 9 arteries (2.18%) and > 50% atherosclerotic stenosis (in term of reduction of the cross-sectional area) was found in 11/156 patients (7%) concerning 14 arteries (3.4%). Accessory renal arteries were found in 66/156 hypertensive patients (42.3%) implicating 84 kidneys (27%) and in 50/112 patients (44.6%) of the normotensive group implicating 67 kidneys (29.9%).

CONCLUSION: With a good protocol, MDCT of the renal arteries is technically interpretable in most patients and can safely rule out atherosclerotic stenosis and/or fibromuscular dysplasia. The systematic cine-review of the native millimetric reconstructions and volume rendering images are the most recommended methods. Direct axial MPR views of the arterial lumen are also possible permitting a precise calculation of the percentage of stenosis from the cross-sectional area of the artery, an advantage on DSA in cases of asymmetrical stenosis. Finally a very high prevalence of multiple renal arteries--the highest ever reported to our knowledge--is found and the prevalence appears similar in both hypertensive and normotensive groups; this high prevalence not only confirms and emphasises the very high sensibility and resolution of MDCT but also definitively disproves the hypothesis that multiple renal arteries could predispose to hypertension.