Renal time-resolved MR angiography: quantitative comparison of gadobenate dimeglumine and gadopentetate dimeglumine with different doses

PURPOSE: Results with different doses of gadobenate dimeglumine and gadopentetate dimeglumine were compared at magnetic resonance (MR) angiography of the renal arteries. The signal-to-noise ratio (SNR) was evaluated as a quantitative measure of image quality. MATERIALS AND METHODS: Sixty consecutive patients (age range, 24-81 years; mean age, 65 years) underwent intraarterial digital subtraction angiography (DSA) and contrast material-enhanced time-resolved MR angiography. DSA was the standard of reference. Fifteen patients received gadopentetate dimeglumine at doses of 0.2 or 0.1 mmol per kilogram of body weight. Fifteen patients received gadobenate dimeglumine at doses of 0.05 or 0.1 mmol/kg. The SNR was calculated in the aorta and both main renal arteries. The number and degree of stenoses of the renal arteries and accessory vessels were evaluated by four observers. RESULTS: SNRs with gadobenate dimeglumine at a dose of 0.1 mmol/kg were significantly superior to those with gadopentetate dimeglumine at a dose of 0.1 mmol/kg. Differences were not statistically significant between the SNRs in the other groups. Eleven (85%) of 13 hemodynamically significant renal artery stenoses were detected correctly with MR angiography as were 22 (85%) of 26 accessory renal arteries. CONCLUSION: SNRs with gadobenate dimeglumine were higher than those with gadopentetate dimeglumine, but in most cases the differences in SNRs were not statistically significant.