Renal artery stenosis: evaluation with breath-hold, three-dimensional, dynamic, gadolinium-enhanced versus three-dimensional, phase-contrast MR angiography

PURPOSE:
To compare breath-hold, three-dimensional, gadolinium-enhanced magnetic resonance (MR) angiography with three-dimensional, phase-contrast MR angiography in the evaluation of renal artery stenosis.
MATERIALS AND METHODS:
Fifty-five consecutive adult patients with clinical suspicion of renovascular disease were prospectively examined with three-dimensional, phase-contrast MR angiography and breath-hold, three-dimensional MR angiography with injection of a standard dose of gadopentetate dimeglumine to evaluate the number of renal arteries and the presence and degree of stenosis. The standard of reference was intraarterial digital subtraction angiography.
RESULTS:
Gadolinium-enhanced MR angiography depicted all 105 main renal arteries, whereas phase-contrast MR angiography depicted 104. The number of accessory renal arteries depicted was significantly higher with gadolinium-enhanced (17 of 18) than with phase-contrast (11 of 18) studies (P = .04). Both techniques depicted 27 of the 29 stenoses (sensitivity, 93%; P > .05). Sensitivities, specificities, and accuracies in the diagnosis of hemodynamically significant stenosis (> 50% narrowing) were, respectively, 94%, 96%, and 96% for phase-contrast and 100%, 97%, and 98% for gadolinium-enhanced MR angiography (P > .05).
CONCLUSION:
Gadolinium-enhanced MR angiography is superior to phase-contrast MR angiography in accessory renal artery depiction. No statistically significant difference in the assessment of stenosis has been found between the two techniques.