Contrast-Enhanced Magnetic Resonance Angiography

Abstract

To assess the gadolinium-based macromolecular intravascular contrast agent P792 for magnetic resonance angiography (MRA) at magnetic field strengths of 3.0 T, in comparison to 1.5 T, in rabbits. Eleven female New Zealand rabbits of the same age served as the animal model. Dose relationship testing was performed with 2 doses (13 and 25 micromol/kg; n = 4 per group) of P792 as compared with a single dose (100 micromol/kg; n = 3) of gadoterate meglumine (Gd-DOTA). All animals underwent contrast-enhanced MRA of the abdominal aorta and its branches on 2 occasions separated by 72 hours. The particular doses were administered in random order. Contrast-enhanced MRA was performed on 3.0 and 1.5 T whole-body MR systems, using a fast 3D spoiled gradient recalled echo sequence. Data acquisition was performed before and up to 10 minutes after administration of intravenous contrast material. Image quality was judged on a 4-point-Likert scale. Signal-to-noise and contrast-to-noise measurements were performed; statistical differences (P < 0.05) between the groups were determined. P792 and Gd-DOTA yielded high-quality MR angiograms in rabbits in all cases. Although image quality within the first 3 minutes after contrast material administration was equal for both agents, P792 at a dose of 25 micromol/kg was considered superior to Gd-DOTA at the later time points. Signal-to-noise and contrast-to-noise values of the higher dose of P792 were statistically significantly higher than those of Gd-DOTA in the post-bolus phase. P792 seems to be well suited for high-quality early phase and equilibrium phase MRA in rabbits at a field strength of 3.0 T, on the basis of this initial evaluation in an animal model.