Combined Cardiac CT and MRI for the Comprehensive Workup of Hemodynamically Relevant Coronary Stenoses

OBJECTIVE. The purpose of our study was to prospectively evaluate the accuracy of a comprehensive assessment of coronary artery disease (CAD) with prospectively ECG-gated coronary CT angiography (CTA) and perfusion-cardiac MRI for the detection of hemodynamically relevant coronary stenoses. SUBJECTS AND METHODS. Forty-seven consecutive patients underwent k-space and time broad-use linear acquisition speed-up technique accelerated perfusion-cardiac MRI at 1.5 T and dual-source coronary CTA. Catheter coronary angiography (CA), coronary CTA, and perfusion-cardiac MRI were all performed within a median time interval of 7.5 days. Detection of hemodynamically relevant stenoses by the combination of coronary CTA plus perfusion-cardiac MRI was compared with the combination of CA plus perfusion-cardiac MRI, the latter serving as the standard of reference. RESULTS. CA identified stenoses in 75 of 141 coronary arteries (53.2%) in 33 of 47 patients (70.2%). Cardiac MRI revealed perfusion defects in 30 of 47 patients (63.8%). Image quality of coronary CTA was diagnostic in 635 of 638 segments (99.5%). Coronary CTA revealed stenoses greater than 50% in 76 of 141 coronary arteries (53.9%) of 33 of 47 patients (70.2%). Sensitivity, specificity, negative and positive predictive value, and accuracy of coronary CTA and perfusion-cardiac MRI versus CA and perfusion-cardiac MRI for the detection of hemodynamically relevant stenoses were 96.7%, 100%, 94.4%, 100%, and 97.9%, respectively. CONCLUSION. The combination of coronary CTA and perfusion-cardiac MRI shows diagnostic performance comparable to that of CA and perfusion-cardiac MRI. Preliminary data suggest that coronary CTA may replace CA in the diagnosis of hemodynamically relevant CAD.