The purposes of this study were to evaluate the feasibility of free-breathing whole heart coronary MR angiography (MRA) in a routine clinical setting, and to determine the accuracy of this method for the detection of coronary artery stenoses.

Whole heart coronary MRA was performed in 153 patients with suspected coronary artery disease. High resolution 3D coronary MR images covering the entire heart were obtained with a navigator-gated, steady state free precession sequence (TR/TE=4.6/2.3ms, flip angle=90 degree, SENSE factor=2, FOV=280x280x120mm, reconstruction matrices=512x512x160). In 39 patients who underwent invasive coronary angiography within two weeks of MR study, the presence of significant stenosis in the coronary artery was assessed on whole heart coronary MRA. All coronary arteries and side branches with a diameter of 1.5mm or more on invasive coronary angiography were evaluated, and luminal diameter reduction of 50% or more on quantitative coronary angiography was considered to be significant.

Acquisition of the whole heart coronary MRA was completed within 20 minutes in 129(84.3%) of 153 patients, with the averaged imaging time of 14.3±5.2 minutes. On invasive coronary angiography, 16 patients had significant coronary artery disease and 14 of these patients were correctly identified by whole heart coronary MRA (sensitivity 87.5%; specificity 91.3%; positive and negative predictive values 87.5% and 91.3%). For detecting significant stenosis in the individual coronary artery, the sensitivity, specificity, positive and negative predictive values of whole heart coronary MRA was 83.3% (20/24), 97.7% (129/132), 87.0% (20/23) and 97.0% (129/133), respectively. The sensitivity and specificity were 100% and 93.9% for RCA, 87.5% and 96.8% for LAD, 75.0% and 100% for LCX, respectively.

Whole heart coronary MRA with a navigator-gated, steady state sequence can provide reliable visualization of the entire coronary arteries with total examination time of less than 30 minutes in a routine clinical setting. This approach allows for the accurate detection of coronary artery disease without exposure to ionizing radiation or injection of contrast medium.