Multi-slice Spire CT Coronary Angiography With Reduction Radiation Dose

Objective:With the enhancement and improvement of the space and time-resolved rate, the technology of multi-slice spire computed tomography coronary angiography can quickly and accurately evaluate the nature of coronary artery stenosis and atherosclerotic plaques, as a kind of non-invasive examination and practical means, it has advantages of high negative predictive value, and for clinical diagnosis of coronary heart disease provides a reliable basis. However, with the thin-layer scanning the widespread use of large volume, it allows for the accumulation of radiation dose produced a relatively high total dose, patients has greatly increased the risk of radiation damage of random effects.To evaluate the impact of ECG mA modulation method of 64-slice spire CT on image quality and X-ray dosage in CT coronary artery imaging, and to explore the best settings of ECG modulated mA.Methods:1.60 patients were randomly divided into four groups,15 included in each group. There was no significant difference in terms of age height and weight and body mass index of every group(P>0.05). All of them checked the CT coronary angiography.2. CT coronary artery images were scanned with tube current modulation by the most tube current of 700 mA,630 mA,560 mA,490 mA, respectively.3. In all groups, the mean effective dose and image quality were calculated and compared with the method used the single factor analysis of variance.Results:1. There were significant differences between image quality by 700 mA and that by 490 mA in CT coronary artery imaging, but there were no significant differences between image quality by 700 mA and that by 630 mA and 560 mA.2. Mean ED of the most tube current of 700 mA was 18.27±4.9 mSv, the Mean ED of the other three groups decreased by 8.6%,17.9%,21.2%.3. There were significant differences between image quality by 700 mA and that by 490 mA in image quality score. The other two groups images can meet the requirements of clinical diagnosis, with the purpose of lowering the radiation dose.Conclusion:Radiation dose can be reduce by controlling the most tube current of CT coronary artery scan with the maintaining the quality of CT image for diagnosis. The investigation testified that the CT coronary artery imaging with 560 mA could meet the requirements of clinical diagnosis in the normal weight group.