Feasibility study of contrast injection scheme based on body mass and iodine flow rate in coronary computed tomography angiography with wide detector CT

Abstract

Objective: To investigate the feasibility of coronary computed tomography angiography (CCTA) with the individualized contrast medium injection scheme based on body mass and iodine flow rate by using wide detector CT at 100 kV. Methods: From May 2018 to July 2018,270 patients with clinically suspected coronary artery disease underwent CCTA in TEDA International Cardiovascular Hospital. They were randomly divided into three groups, 90 cases in each group: group A was 0.5 ml/kg, group B was 0.6 ml/kg, the flow rate of contrast medium injection in group A and group B was (body mass×25 mg)/the concentration of contrast medium,group C was 0.8 ml/kg and the flow rate of contrast medium was 5 ml/s. Iohexol (iodine concentration 350 mgI/ml) was used in all three groups. The CT values of the aorta root in the three groups, the CT value of the middle segment of LAD and RCA, SNR、CNR、SD of the aortic root, subjective score of coronary artery and effective dose (ED) were compared. Results: There was no significant difference in CT value of aortic root, CT value of middle LAD and RCA, SNR、CNR、SD of the aortic root, subjective score of coronary artery among group A, group B and group C (all P>0.05). The flow rates of the three groups of contrast agents were statistically different (4.5±0.5 vs 4.5±0.5 vs 5, P=0.015), and there was no statistical difference between group A and group B (P>0.05) but lower than group C (P=0.015); the amount of contrast agent in the three groups was statistically different (32±3 vs 38±4 vs 53±7, P<0.001), group A<B Group<C group; there was no significant difference in ED between the three groups (1.5±0.5 vs 1.5±0.6 vs 1.3±0.6, P=0.613). Conclusions: CCTA imaging with a wide body detector based on a 0.5 ml/kg contrast agent dosage and a flow rate of ((body mass × 25)/350) ml/s individualized injection scheme can ensure the image quality while reducing the total amount of contrast agent and realizing individualized iodine flow rate.