Clinical research of dose reduction protocol in coronary artery CT angiography with discovery 750 HD

Abstract

Objective To evaluate effects on image quality and effective radiation with the dose reduction protocol adapted by body mass index (BMI) in coronary artery CT angiography with discovery 750 HD.Methods Two hundred and seven patients suspected with coronary artery disease (CAD) were enrolled in Group A who were underwent CT angiography with routine radiation,and another 242 patients were enrolled in Group B who received a new scanning protocol with tube voltage and tube current modulation depending on the BMI.The scores of image quality,signal noise ratio(SNR),CT dose index (CTDIvol),and effective dose (E) were compared and the correlation between the scanning parameters and E was analyzed.Results The mean radiation dose in Group B (1.2,ranging from 0.8 to 2.5 mSv) was significantly lower than that in Group A (1.9,ranging from 1.5 to 2.3 mSv ; Z =-6.24,P ＜ 0.05).The multivariate regression analysis revealed that the first factor affecting effective radiation dose ranked as scanning mode,tube voltage,tube current,and scan length,respectively.The image quality between two groups was not significantly different.The SNR in Group B was greater than that in Group A (Z =-2.22,P ＜0.05).Conclusions Dose reduction protocol in coronary artery CT angiography with discovery 750 HD would help to reduce the radiation dose effectively without sacrificing image quality. Key words: Dose reduction; Coronary angiography; Tomography, X-ray computed