Diagnostic performance of low-radiation-dose and low-contrast-dose (double low-dose) coronary CT angiography for coronary artery stenosis

The aim of the present study was to evaluate the diagnostic accuracy of low-radiation-dose and low-contrast-dose (double low-dose) coronary computed tomography angiography (CTA) for coronary artery stenosis in patients with suspected coronary artery disease (CAD). Totally 88 patients with suspected CAD were divided in the routine and double low-dose groups. Subjective image quality (IQ) was scored and diagnostic performance for detecting ≥50% stenosis was determined with the invasive coronary angiography. IQ and diagnostic performance were analyzed and compared between the 2 groups. There was no significant difference in the IQ of coronary artery between the routine and double low-dose groups, with good inter-observer agreement for the IQ. There were no significant differences in the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy on the per-patient, per-vessel, or per-segment level between the routine and double low-dose groups. The contrast medium injection volume in the double low-dose group was reduced by 37.1% compared with the routine-dose group. The effective dose in the double low dose was reduced by 44.5% compared with the routine-dose group. Double low-dose coronary CTA with IR can acquire satisfactory IQ and have high diagnostic sensitivity, specificity, and accuracy for the detection of coronary artery stenosis.