Three-dimensional MR coronary angiography using the navigator technique compared with conventional coronary angiography

OBJECTIVE. We evaluated the diagnostic accuracy of three-dimensional (3D) M R coronary angiography with the navigator technique for the detection of co ronary artery stenoses in comparison with that of conventional radiographic angiography. SUBJECTS AND METHODS. Thirty patients with coronary artery disease were exa mined with an EGG-triggered 3D fast low-angle shot sequence using retrospec tive respiratory gating and the navigator technique on a 1.5-T MR scanner. The data set was evaluated as a 3D view with a surface rendering technique. RESULTS. Imaging of the proximal coronary arteries was possible in all pati ents. The average visualized lengths of the left main, left anterior descen ding, left circumflex, and right coronary arteries were 1.9 +/- 0.5 cm (mea n +/- SD), 5.2 +/- 2.3 cm, 4.2 +/- 1.9 cm, and 5.2 +/- 2.5 cm, respectively . Irregular breathing reduced image quality in seven of the 30 patients, ma king diagnosis of stenoses impossible. In the 77% of patients whose examina tions resulted in high-quality images, the sensitivity and specificity for detection of significant stenoses and occlusions in all four main coronary arteries were 81% and 89%, respectively. CONCLUSION. The navigator technique allows reproducible imaging of the prox imal course of coronary arteries. This technique obviates breath-hold studi es, thus allowing more patients to be examined. In patients whose examinati ons resulted in high-quality images, significant coronary artery lesions co uld be seen. However, for widespread clinical use, further technical improv ement is necessary to increase sensitivity and specificity.