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.