ASSESSMENT OF CORONARY-ARTERY STENOSES US ING RESPIRATORY GATED MR-ANGIOGRAPHY

Respiratory gated MR coronary angiography is a new MR imaging techniqu e which permits reconstruction of the coronary arteries from a three-d imensional data set obtained from contiguous parallel sections. In thi s study, respiratory gated MR angiography was applied to assess signif icant coronary artery stenoses (greater than or equal to 50%). MR imag ing was performed in 68 patients (50 men, 18 women) who had been refer red to cardiac catheterization because of suspected or known coronary artery disease. The evaluation of coronary artery stenoses was perform ed in a blinded manner in the proximal, middle, and distal vessel segm ents after multiplanar coronary reconstruction of the MR images. Of th e 680 coronary segments, 275 (40%) were located outside the imaging vo lume and were, therefore, excluded from further analysis. The highest sensitivity for stenosis detection was found in the proximal left ante rior descending (LAD) and right coronary artery (RCA) with 75% and 71% , respectively. The overall sensitivity, however, was low with 48%. Th e overall specificity was 92%. The positive and negative predictive va lues were 67% and 85%, respectively. This study shows that significant coronary artery stenoses, especially in the proximal LAD and RCA, can be correctly identified using respiratory gated MR angiography. Howev er, further technical improvements are necessary before this method ma y become a reliable diagnostic tool in clinical practice.