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.
From the *Scott & White Clinic & Hospital, Department of Radiology, Temple; †University of Texas Medical Branch (UTMB), Department of Radiology, Galveston, TX; ‡Tongji Hospital, Huazhong University of Science and Technology, Department of Radiology, Wuhan, HuBei, China; §Siemens Healthcare Erlangen, Bavaria, Germany; ∥Siemens Medical Solutions USA, Dallas, TX; ¶Texas A&M University, Institute for Preclinical Studies (TIPS), College Station; #University Hospital Giessen, Diagnostic Radiology, Giessen, Hessen; and **University Medical Center Mannheim, Institute of Clinical Radiology and Nuclear Medicine, Mannheim, Baden-Württemberg, Germany.
Received September 13, 2011; and accepted for publication, after revision, January 10, 2012.
Conflicts of interest and sources of funding: none declared.
Reprints: Xiaoming Li, MD, PhD, Tongji Hospital, Huazhong University of Science and Technology, Department of Radiology, Wuhan, Hubei 430030 China. E-mail: firstname.lastname@example.org.