Application of 80-kVp tube voltage, low-concentration contrast agent and iterative reconstruction in coronary CT angiography: evaluation of image quality and radiation dose

Abstract

To evaluate image quality and radiation dosage in coronary CT angiography using 80-kVp tube voltage combined with low-concentration contrast media (CM) and iterative reconstruction (IR) for coronary CT angiography (CCTA) and employing dual-source CT without heart-rate control. 154 patients were randomly assigned to Group A (Control Group, 120-kVp tube voltage, high-concentration CM and filtered back projection reconstruction) and Group B (Low-Dose Group, 80kVp, low-concentration CM and iterative construction). Two experienced radiologists double-blindly evaluated the following parameters: CT attenuation, signal-noise ratio (SNR), contrast-noise ratio (CNR), radiation dose, size-specific dose estimates (SSDE) and total iodine intake. Pearson correlation analysis was used to assess the relationship between SSDE and BMI. 98.1% vessel segments in Group A and 97.6% in Group B passed diagnostics, indicating no significant differences; the average aorta scores and CT attenuation values showed no significant differences between groups. Similar SNR and CNR results were obtained for the two groups, although values were slightly lower in Group A compared with Group B. The Effective Dose in Group B was 63% lower than that in Group A (P<.001). SSDE results were significantly different between the two groups (P<.001) but did not correlate with BMI. Finally, the total iodine intake in Group B was 22.9% lower than that in Group A. Coronary CTA conducted with a low tube voltage of 80kVp, a low-concentration CM and IR without heart rate control can achieve images of similar quality to those obtained using standard procedures, significantly reducing the associated radiation dose and iodine intake.