Clinical Study Of Low Tube Voltage And Low Dose Contrast Medium Combined With Adaptive Statistical Iterative Reconstruction-V Technology For Coronary CT Angiography

Objective:Low dose contrast medium combined with adaptive statistical iterative reconstruction-V(ASiR-V)technique,regulate the different tube voltage of coronary artery CT angiography scan,calculate and analyze the radiation dose and the degree of vascular enhancement,the tube voltage is optimized.Further application of conventional concentration contrast agent,conventional tube voltage for coronary CT scan,compared with low concentration contrast agent,optimized tube voltage for the relevant parameters.And to explore the feasibility of low tube voltage,low dose contrast agent combined with adaptive statistical iterative reconstruction-V(ASiR-V)technique in coronary artery CT imaging.Materials and Methods:Collection of June 2017 patients with clinically suspected coronary heart disease with coronary artery CT angiography examination of eighty cases at the First Hospital of Jilin University.We randomly divided into four groups(A,B,C and D),20 cases in each group.Group A,B and C received isotonic low-dose contrast agent Visipaque(270mg/ml),with tube voltage set to 80 kV-120 kV.Group D patients received conventional concentration contrast agent iopromide(370 mg/ml),with conventional tube voltage 120kV.All the remaining scan parameters are consistent.All raw data were processed by adaptive statistical iterative reconstruction-V(ASiR-V,50%).Statistical software was used to analyze and compare the radiation dose and image quality among groups A,B and C,and selected the optimal dose of kV.Finally,we compared differences between the best kV group and group D.Results:1.When the concentration of contrast media is fixed,there is a trend that the CTDIvol,DLP and ED gradually increased with the increase of tube voltage.Differences in CTDIvol,DLP and ED between the groups A,B and C were statistically significant(P<0.001).The SD decreased with the increase of the tube voltage.On the other hand,the SNR and CNR increased with the increase of the voltage.Differences in SD,SNR and CNR between the groups A,B,and C were statistically significant(P<0.001).There were no significant differences in mean CT attenuation between the proximal segment of the three main coronary arteries(RCA,LAD and LCX,P>0.05).Image quality subjective evaluation of the difference among the groups A,B,and C was not statistically significant(x~2=2.19,P=0.34).That is,80kV is the best kV.2.The differences in CTDIvol,DLP and ED between groups A("Double Low")and D("Traditional")were statistically significant(P<0.001).The radiation dose in group A was significantly lower than that of group D.The differences in SD,SNR and CNR between groups A and D were statistically significant(P<0.001).There were no significant differences in mean CT attenuation between the RCA proximal segment,LAD proximal segment,and LCX proximal segment(P>0.05).Image quality subjective evaluation of the difference between the two groups was not significant(x~2=1.14,P=0.71).Ideal image quality was obtained at80kV tube voltage with Visipaque(270 mg/ml)contrast agent.Conclusion:Low tube voltage and low dose contrast agent combined with adaptive statistical iterative reconstruction-V(ASi R-V)in coronary CT imaging,reduces the dose of radiation while ensuring that image quality.