Feasibility of coronary artery angiography using descending aorta bolus tracking area of interest

DING Yi; SONG Bin; XU Jingjing; ZHU Shizhen

Abstract：Objective To evaluate the feasibility of using descending aortic bolus to track the region of interest in coronary CT angiography(CCTA).Methods 67 patients clinically suspected coronary heart disease with heart rate≤60 beats/min were scanned by two different protocols:patients in group A and B,the area of interest of bolus tracking was placed in the ascending aorta and the descending aorta,respectively.The trigger success rates of the two groups were recorded.The regions of interest were selected in the aortic root,the left main coronary artery,the proximal left anterior descending artery,left circumflex artery,and the right coronary artery respectively.Enhancement and noise of the coronary artery were quantified,and Signal-to-noise(SNR)and contrast-to-noise ratios(CNR)was calculated.The image quality of the two groups was subjectively evaluated by two senior radiologists using 4-point method.Statistical differences were analyzed by independent sample t test and chi-square test.Results Among the 36 cases in group A,2 cases were falsely triggered,and 34 cases were successfully triggered,with the suc-cess rate of 94.4%.31 cases in group B were all triggered successfully(100%).The enhanced CT values,SNR and CNR of each target vessels in group B were higher than those in group A.Among them,the enhanced CT values of the left main coronary ar-tery,the proximal left anterior descending artery in group B were statistically significantly higher than those in group A(P<0.05).Conclusion Using the descending aortic bolus injection to track the region of interest based on the third-generation dual-source CT with large-pitch was feasible with high trigger success rate and enhanced CT values.