Scott & White Clinic & Hospital, Department of Radiology, Temple, TX, USA.
Invest Radiol. 2012 Jun;47(6):376-82. doi: 10.1097/RLI.0b013e3182539554.
The aim of this study was to compare low-dose imaging with gadobutrol and gadoterate meglumine (Gd-DOTA) for evaluation of renal artery stenosis with 3-T magnetic resonance angiography (MRA) in a swine model.
A total of 12 experimental animals were evaluated using equivalently dosed gadobutrol and Gd-DOTA for time-resolved and static imaging. For time-resolved imaging, the time-resolved imaging with stochastic trajectories (TWIST) technique (temporal footprint, 4.4 seconds) was used; a dose of 1 mL of gadobutrol was injected at 2 mL/s and a dose of 2 mL of Gd-DOTA was injected at both 2 and 4 mL/s. For a separate static acquisition, doses were doubled. The static scans were used for stenosis gradation and the time-resolved scans for comparison of enhancement dynamics, signal-to-noise ratio (SNR), and qualitative assessments.
The average magnitude of difference in the stenosis measurements with static gadobutrol scans relative to digital subtraction intra-arterial catheter angiography (mean [SD], 7.4% [5.6%]) was less than with both the 2 mL/s (10.6% [6.2%]) and 4 mL/s (11.5% [7.8%]) Gd-DOTA MRA protocols. On time-resolved scans, peak signal-to-noise ratio was greatest with the gadobutrol protocol (P < 0.05), and the gadobutrol TWIST scan was preferred to the TWIST Gd-DOTA scan in terms of image quality and stenosis visualization in every case for every reader.
Low-dose gadobutrol (~0.05 mmoL/kg) contrast-enhanced MRA results in improved accuracy of renal artery stenosis assessments relative to equivalently dosed Gd-DOTA at 3 T.
本研究旨在比较低剂量钆布醇和钆特酸葡甲胺（Gd-DOTA）在猪模型中进行 3T 磁共振血管造影（MRA）评估肾动脉狭窄的效果。
总共对 12 只实验动物进行了等效剂量的钆布醇和 Gd-DOTA 的时间分辨和静态成像评估。对于时间分辨成像，使用时间分辨成像随机轨迹（TWIST）技术（时间足迹，4.4 秒）；以 2mL/s 的速度注射 1mL 钆布醇，以 2 和 4mL/s 的速度分别注射 2mL 和 4mL 的 Gd-DOTA。对于单独的静态采集，剂量加倍。静态扫描用于狭窄分级，时间分辨扫描用于比较增强动力学、信噪比（SNR）和定性评估。
相对于数字减影动脉内导管血管造影（平均[标准差]，7.4%[5.6%]），静态钆布醇扫描的狭窄测量平均差异幅度小于 2mL/s（10.6%[6.2%]）和 4mL/s（11.5%[7.8%]）Gd-DOTA MRA 方案。在时间分辨扫描中，峰值 SNR 最高的是钆布醇方案（P<0.05），在每个病例和每个读者中，钆布醇 TWIST 扫描在图像质量和狭窄可视化方面都优于 TWIST Gd-DOTA 扫描。
与等效剂量的 3T Gd-DOTA 相比，低剂量钆布醇（~0.05mmol/kg）对比增强 MRA 可提高肾动脉狭窄评估的准确性。
