Contrast-enhanced magnetic resonance angiography: evaluation of the high relaxivity low diffusible gadolinium-based contrast agent P846 in comparison with gadoterate meglumine in rabbits at 1.5 Tesla and 3.0 Tesla.

Objectives: To evaluate the gadolinium-based contrast agent P846 and compare it with gadoterate meglumine (Gd-DOTA) for contrast-enhanced magnetic resonance angiography (MRA) in rabbits at 1.5 T and 3.0 T, respectively. Materials and Methods: Five rabbits underwent contrast-enhanced MRA of the abdominal vasculature applying gadolinium doses of 0.025 mmoL/kg for P846 and 0.1 mmoL/kg for Gd-DOTA, respectively. All animals were examined on a 1.5-T and 3.0-T MR system. Image data were acquired during the first-pass arterial phase and repeatedly over 10 minutes. Contrast-to-noise-ratio (CNR) was determined in the aorta, the inferior vena cava, and the renal cortex. Image quality of arterial phase MR angiograms was consensually judged on a 5-point scale (5 = high). Results: Contrast-enhanced MRA was successful in all cases with both contrast agents. CNR values consistently proved statistically significantly higher for P846 compared with Gd-DOTA. CNR values in the aorta during the arterial phase were 46.0 ± 3.7 (P846) and 28.0 ± 3.2 (Gd-DOTA) at 1.5 T (P < 0.05), and correspondingly 89.3 ± 12.7 (P846) and 64.1 ± 15.0 (Gd-DOTA) at 3.0 T (P < 0.05). Image quality of arterial phase MR angiograms was rated with scores of 4.8 ± 0.4 (P846) and 4.0 ± 0.0 (Gd-DOTA) at 1.5 T (P = 0.06), and 5.0 ± 0.0 (P846) and 4.8 ± 0.4 (Gd-DOTA) at 3.0 T (P = 0.42), respectively. Conclusions: The contrast agent P846 provides high contrast enhancement and image quality for contrast-enhanced MRA in rabbits at 1.5 T and 3.0 T with a 4-fold lower gadolinium dose compared with a standard extracellular contrast agent.