ABSTRACT
Objective To investigate the feasibility of using low Kv,low iodine contrast Agent concentration (dual low)CT scan techniques in Coronary CTA (CCTA).Methods Seventy-six patients undergoing CCTA were divided into Group A and Group B , randomly.Group A (38 patients)was the dual-low group,which was scanned with tube voltage of 100 kVp,and injected with iso-osmolarity contrast agent visipaque 270 (270 mg I/mL),with iterative reconstruction technique (ASIR 40%).Group B (38 pa-tients)was scanned with 120 kVp,and low osmolarity contrast agent omnipaque 350 (350 mg I/mL)and FBP reconstruction,The images are assessed double-blindly by two experienced radiologists.Five ROIs were placed onto the ascending root of aorta (AO), left main artery(LM),left anterior descending (LAD),left circumflex artery(LCX),right coronary artery (RCA),and the image qualities are evaluated objectively using CT values,noise,signal noise ratio (SNR),contrast noise ratio (CNR),and compared sta-tistically using Paired t-test.The radiation dosages,such as CTDIvol,DLP and ED were also recorded and compared with Paired t-test.Results CTDIvol,DLP and ED of Group A (dual low)decreased 35.7%,38.6% and 38.6% respectively compared with Group B,the iodine intake decreased 22.9%.While the image qualities of the two groups were not significantly different,all images are good enough for diagnosis,with Group A slightly better than Group B in radiologists’scores.Conclusion Voltage 100 kVp, combined with low contrast agent concentration of 270 mg I/mL can fully satisfy the diagnostics need in CCTA,and significantly lower both the radiation dosage and iodine intake.