Three-dimensional MRI of coronary arteries using an intravascular contrast agent.

To assess the effectiveness of an intravascular contrast agent, MS-325, for enhancing the vascular signal in coronary MR angiograms, six minipigs were studied using a three-dimensional, gradient-echo sequence with retrospective respiratory gating. To suppress the myocardial signal, preparatory RF pulses were applied before data acquisition. With the administration of MS-325, the blood signal-to-noise ratio increased by 97-276%, depending on the region of interest in which the blood signal was measured and the precontrast imaging sequence structures. The blood/myocardium contrast-to-noise ratio also significantly increased. High-resolution images (0.58 x 0.58 x 1 mm3) obtained from postmortem pig hearts demonstrated the potential delineation of coronary arteries with MS-325. In conclusion, this study supports further evaluation of the utility of MS-325 in improving coronary MR angiography in humans.