Fat-suppressed breath-hold magnetic resonance coronary angiography

Abstract

Background: The ability to image the coronary arteries noninvasively would represent an advance in patient care. We have developed a magnetic resonance (MR) angiographic technique that allows the acquisition of complete images of coronary flow within a single breath-hold. By this method, the feasibility of noninvasive MR coronary angiography was evaluated in 25 subjects, including 19 healthy adult volunteers and six patients after diagnostic coronary angiography.

Methods and results: Noninvasive MR coronary angiography was performed with a fat-suppressed ECG-gated gradient-echo sequence with k-space segmentation. Overlapping transverse sections were initially used to image coronary flow, with oblique images obtained after identification of proximal anatomy. The left main coronary artery was seen in 24 subjects (96%), with a mean diameter of 4.8 mm (range, 3.4-6.2 mm) and average length of 10 mm (range, 8-14 mm). The left anterior descending coronary artery was seen in 100% of subjects, with a mean proximal diameter of 3.6 mm (range, 2.6-4.3 mm) and for an average length of 44 mm (range, 28-93 mm). The left circumflex coronary artery was seen in 76% of subjects, with a mean proximal diameter of 3.5 mm (range, 2.6-4.3 mm) and for an average length of 25 mm (range, 9-42 mm). The right coronary artery was also identified in 100% of subjects, with a mean proximal diameter of 3.7 mm (range, 2.7-5.1 mm) and for an average length of 58 mm (range, 24-122 mm). Quantitative angiography of normal proximal segments demonstrated a good correlation with MR-determined lumen diameters (r = 0.86, p < 0.002). Occluded vessels in patients with coronary artery disease displayed an absence of flow signal distal to the occlusion, whereas vessels with significant angiographic stenoses demonstrated signal loss corresponding to the area of the stenosis, with visualization of the more distal vessel.

Conclusions: Breath-hold MR coronary angiography provides visualization of the major epicardial vessels. In the future, MR coronary angiography may provide a noninvasive means for the evaluation of patients with known or suspected coronary artery disease.