Purpose:To investigate the feasibility of high-resolution selective three-dimensional (3D) magnetic resonance coronary angiography (MRCA) in the evaluation of coronary artery stenoses.
Materials and Methods:In 12 patients with coronary artery stenoses, MRCA of the coronary artery groups, including the coronary segments with stenoses of 50% or greater based on conventional x-ray coronary angiography (CAG), was performed with double-oblique imaging planes by orienting the 3D slab along the major axis of each right coronary artery-left circumflex artery (RCA-LCX) group and each left main trunk-left anterior descending artery (LMT-LAD) group. Ten RCA-LCX and five LMT-LAD MR angiograms were obtained, and the results were compared with those of conventional x-ray angiography.Results: Among 70 coronary artery segments expected to be covered, a total of 49 (70%) segments were fully demonstrated in diagnostic quality. The identification of segmental location of stenoses showed as high an accuracy as 96%. The retrospective analysis for stenosis of 50% or greater yielded the sensitivity, specificity, and accuracy of 80%, 85%, and 84%, respectively.
Conclusion:Selective 3D MRCA has the potential for segment-by-segment evaluation of major portions of the right and left coronary arteries with high accuracy. THE DESIRE TO REPLACE CONVENTIONAL x-ray coronary angiography (CAG) by a less invasive imaging method is commonplace. Magnetic resonance coronary angiography (MRCA) has been evaluated by many authors since the late 1980s (1-16). Electrocardiography (ECG)-gated breath-hold and navigator-echo guided data acquisition have been evaluated to overcome image blurring due to cardiac and respiratory motion during the relatively long MR data acquisition process. Many imaging strategies have focused on the detection and quantification of the stenoses of only the proximal coronary arteries, but detection and quantification of the stenoses still remain unreliable (4,8,12,15).Transaxial sections used in those studies usually cover only the proximal segments of the major coronary arteries (8,12). However, not only the proximal coronary arteries, but also the mid and distal coronary arteries can be involved in the ischemic heart diseases. If all of the coronary arteries are covered with the transaxial imaging plane (12)(13)(14), the imaging time would be prolonged in association with large volume acquisition, and the right coronary artery could not be obtained with high spatial resolution because it runs in the through-plane direction. Thus, by orienting the threedimensional (3D) imaging slab along the major axis of the coronary vessels, coronary coverage can be more optimal with smaller imaging volumes (16). Recently, some investigators have used axial orientations for the left main trunk (LMT), proximal and mid left anterior descending artery (LAD), and proximal left circumflex artery (LCX), and oblique orientations for the right coronary artery (RCA) (17,18). However, two double-oblique scan volumes, when oriented along the atrioventri...
