Evaluation of dynamic gadolinium-enhanced breath-hold MR angiography in the diagnosis of renal artery stenosis

OBJECTIVE. The aim of our study was to evaluate a three-dimensional gadolin ium-enhanced breath-hold MR angiography sequence using standard MR gradient s in detecting renal artery stenosis. SUBJECTS AND METHODS. Forty-two patients referred for angiography for suspe cted renal artery stenosis underwent both conventional digital subtraction angiography (DSA) and MR angiography. MR angiography was performed on a 1.5 -T scanner with standard gradients. A fast multiplanar spoiled gradient-ech o sequence was used with the following parameters: TR/TE, 10.3/1.9; flip an gle, 45 degrees; field of view, 36 x 32 cm; matrix size, 256 x 128; one exc itation; volume thickness, 70 mm; and partitions, 28. Gadolinium was admini stered IV as a dynamic bolus of 30-40 mi. Conventional and MR angiographic images were interpreted by two radiologists in consensus. RESULTS, DSA revealed 87 renal arteries, of which 79 were in 35 patients wi th native kidneys and eight arteries were in seven patients with transplant ed kidneys. Gadolinium-enhanced MR angiography showed 85 (98%) of 87 renal arteries. Seventeen patients had 20 significant (>50% stenosis) for renal a rtery stenoses and five patients had five occluded renal arteries revealed by DSA. MR angiography revealed 85 renal arteries (98%), 20 stenoses (100%) , and five occlusions (100%). Gladolinium-enhanced MR angiography led to on e false-positive interpretation for renal artery stenosis and no false-nega tive interpretations. Thus, the sensitivity, specificity, and accuracy of M R angiography for renal artery stenosis were 100%, 98%, and 99%, respective ly. CONCLUSION. The MR angiography pulse sequence we used was an effective and reliable technique for the diagnosis of renal artery stenosis. The sequence can be performed on widely available MR equipment that does not require fa st gradient hardware.