Clinical value of 70 kV combined with low contrast agent CT scan in the diagnosis of pediatric coronary artery disease

Abstract

Objective DSA and/or surgery was used as a control to evaluate the image quality, radiation dose and diagnostic efficacy of 70 kV combined with low contrast agent dose and 80 kV dual-source CT scanning of coronary artery. Methods Between Apr, 2012 and Apr, 2017, a total of 150 consecutive pediatrics with suspected or confirmed coronary arterial diseases underwent DSCTCA, and the patients were randomly divided into 3 groups by different scanning protocols. Group A (n=50): 80 kV with 1.5 ml/kg contrast agent; Group B (n=50): 70 kV with 1.5 ml/kg contrast agent;Group C (n=50): 70 kV with 1.0 ml/kg contrast agent. ANOVA was used to compare the differences of subjective coronary arteries image quality between the three groups;The t-test was used to compare the difference in effective radiation dose between the 70 kV group and the 80 kV group; The surgery and/or angiography results were used as gold standard to evaluate the diagnostic efficacy of the three groups. Results All patients underwent DSCTCA successfully and satisfactory diagnostic images were gained. The mean scores of subjective image quality of coronary artery were 3.5±0.7, 3.4±0.6, 3.7±0.8, respectively. There was no significant difference between the3 groups (F=2.042, P=0.133). The diagnostic accuracy of the three groups for coronary artery disease was 100%, as the surgical and/or angiographic results were used as gold standard. The effective radiation doses in 80 kV group (A group) and the 70 kV group (B+C group) were (0.49±0.04) and (0.30±0.03) mSv, respectively, with a statistically significant difference (t=4.037, P=0.001). Conclusions DSCTCA can better display and diagnose pediatric coronary artery lesions with 70 kV tube voltage combined with low contrast agent, and has a high diagnostic accuracy. It is a reliable method for diagnosing pediatric coronary artery disease. Key words: Child; Coronary arterial disease; Tomography, X-ray computed; Radiation dosage