Dynamic and Static Magnetic Resonance Angiography of the Supra-aortic Vessels at 3.0 T Intraindividual Comparison of Gadobutrol, Gadobenate Dimeglumine, and Gadoterate Meglumine at Equimolar Dose

Purpose: The purpose of this study was the intraindividual
comparison of a 1.0 M and two 0.5 M gadolinium-based contrast
agents (GBCA) using equimolar dosing in dynamic and static magnetic
resonance angiography (MRA) of the supra-aortic vessels. Materials
and Methods: In this institutional review board-approved study, a
total of 20 healthy volunteers (mean +/- SD age, 29 +/- 6 years)
underwent 3 consecutive supra-aortic MRA examinations on a 3.0 T
magnetic resonance system. The order of GBCA (Gadobutrol,
Gadobenate dimeglumine, and Gadoterate meglumine) was randomized
with a minimum interval of 48 hours between the examinations.
Before each examination and 45 minutes after each examination,
circulatory parameters were recorded. Total GBCA dose per MRA
examination was 0.1 mmol/kg with a 0.03 mmol/kg and 0.07 mmol/kg
split for dynamic and static MRA, respectively, injected at a rate
of 2 mL/s. Two blinded readers qualitatively assessed static MRA
data sets independently using pairwise rankings (superior,
inferior, and equal). In addition, quantitative analysis was
performed with signal-to-noise ratio (SNR) and contrast-to-noise
ratio (CNR) evaluation as well as vessel sharpness analysis of
static MRA using an in-house-developed semiautomated tool. Dynamic
MRA was evaluated for maximal SNR. Statistical analysis was
performed using the Cohen kappa, the Wilcoxon rank sum tests, and
mixed effects models. Results: No significant differences of
hemodynamic parameters were observed. In static MRA, Gadobutrol was
rated superior to Gadoterate meglumine (P < 0.05) and equal to
Gadobenate dimeglumine (P = 0.06) with good to excellent reader
agreement (kappa, 0.66-0.83). In static MRA, SNR was significantly
higher using 1.0 M Gadobutrol as compared with either 0.5 M agent
(P < 0.05 and P < 0.05) and CNR was significantly higher as
compared with Gadoterate meglumine (P < 0.05), whereas CNR
values of Gadobutrol data sets were not significantly different as
compared with Gadobenate dimeglumine (P = 0.13). Differences in CNR
between Gadobenate dimeglumine and Gadoterate meglumine were not
significant (P = 0.78). Differences in vessel sharpness between the
different GBCAs were also not significant (P > 0.05). Maximal
SNR in dynamic MRA using Gadobutrol was significantly higher than
both comparators at the level of the proximal and distal internal
carotid artery (P < 0.05 and P < 0.05; P < 0.05 and P <
0.05). Conclusions: At equimolar doses, 1.0 M Gadobutrol
demonstrates higher SNR/CNR than do Gadobenate dimeglumine and
Gadoterate meglumine, with superior image quality as compared with
Gadoterate meglumine for dynamic and static carotid MRA. Despite
the shortened bolus with Gadobutrol, no blurring of vessel edges
was observed.