Equilibrium phase MR angiography using new blood pool contrasts: experimental study in rabbits

The purpose of this study was to evaluate the usefulness of three experimental blood pool contrast agents for equilibrium phase magnetic resonance angiography. MR angiography was performed in 21 rabbits before and 1 , 5, 10, 20 and 30 minutes and 24 hours after the injection of gadolinium-based blood pool contrast agents (Gadomer-17, Gadofluorine M), and superparamagnetic iron oxide blood pool agent (Ferucarbotran). 3D TOF SPGR images of the thoracic and abdominal aorta (and involving the renal arteries) were obtained. The signal difference-to noise ratios (SDNRs) were measured over time in the aorta. These images were then compared to that of images with Gd-DTPA. MR angiography with the three blood pool agents yielded excellent visualization results of the rabbit abdominal aorta. At the same dose, the three agents provided a significant increase of the aorta-to-tissue SDNR in comparison with that achieved with the Gd-DTPA (a 250% increase for Gadomer-17, a 124% increase for Gadofluorine and a 88% increase for Ferucarbotran). The SDNRs using Ferucarbotran especially showed continuously increasing values to 30 minutes after the injection of contrast agent. The three blood pool agents were found to be very useful contrast agents for equilibrium phase MR angiography