Purpose:
To compare a magnetization-prepared gradient-echo (gre) sequence with a conventional gre sequence for visualizing contrast agent-filled catheters.
Materials and methods:
Passive visualization of endovascular catheters using mri was compared between two imaging sequences: 1) inversion recovery (ir)-fast low angle shot (flash), and 2) conventional flash. two-dimensional projection images of the catheters filled with 4% diluted contrast agent in a phantom and the aorta of swine were obtained with each sequence with a temporal resolution of two frames per second. we compared background suppression and catheter visibility using the catheter-to-background signal ratio and the ratings of two radiologists.
Results:
In the phantom, ir-flash allowed for a 200% increase in catheter-to-background ratio (p < 0.01) and improved depiction of catheters over conventional flash. in swine, the ir-flash images showed a statistically significant improvement of 80% (p < 0.001) over conventional flash in all comparisons of the catheter-to-background signal ratio, and an improvement of 160% (p < 0.05) in comparison with the radiologists' observations.
Conclusion:
This study shows that ir-flash is a better technique for passive tracking of contrast agent-filled catheters than conventional flash.