Feasibility of 64-slice gadolinium-enhanced cardiac CT for the evaluation of obstructive coronary artery disease

Objective: To assess the feasibility of gadolinium-enhanced 64-slice cardiac CT (CCT) for the diagnosis of obstructive coronary artery disease. Design: Comparative prospective study. Setting: Outpatient Imaging Diagnostic Centre, Diagnóstico Maipú, Buenos Aires, Argentina. Patients: Twenty patients with suspected coronary artery disease. Interventions: Gadolinium-enhanced 64-slice CCT was performed before invasive coronary angiography (ICA). Main outcome measures: The feasibility of gadolinium-enhanced 64-slice CCT for detection of obstructive coronary artery disease (>50% diameter reduction) was evaluated, using ICA as the 'gold standard'. Mean lumen attenuation, non-calcified and calcified plaques densities were correlated between gadolinium-enhanced CCT studies and iodine-enhanced CCT studies of a control group. Renal function was strictly monitored. Results: Gadolinium-enhanced CCT demonstrated adequate visualisation of 283/289 coronary segments that were evaluable by ICA, 31 of which had >50% luminal stenosis. In per-segment analysis, gadolinium-enhanced CCT showed a sensitivity of 90.3%, specificity of 96.8%, positive predictive value of 77.8% and negative predictive value of 98.8%. The agreement of coronary stenosis between multidetector CT (MDCT) and ICA was 94.1% (272/289). The mean lumen attenuation, non-calcified and calcified plaques densities in gadolinium-enhanced CCT studies were 140.1 Hounsfield units (HU), 51.1 HU and 523.6 HU, whereas in iodine-enhanced CCT studies the values were 354.1 HU, 101.0 HU and 778.5 HU, respectively (p < 0.001). Conclusion: Gadolinium-enhanced CCT is a feasible alternative for patients with severe contraindications to iodinated contrast agents referred for MDCT coronary angiography.