应用心电脉冲和四维管电流调制技术降低128层螺旋CT冠状动脉成像的辐射剂量的研究

目的评价心电脉冲（ECG—pulsing）和四维管电流调制（CAREDose 4D）相结合的毫安调制技术对降低CT冠状动脉成像射线剂量的价值及其对图像质量的影响。方法连续选取配合良好、心率控制在75次／min以下且心律齐的受检者68例，采用完全随机化分组方法分为2组，组1（34例）使用传统方法进行CT冠状动脉成像检查；组2（34例）使用ECG—pulsing及CAREDose 4D技术。通过CT计算机自动生成的剂量长度乘积（DLP），计算出相应的有效剂量（ED）。获得的图像通过双盲法进行质量评分，对两组ED值及图像质量评分用t检验进行比较。结果（1）组1和组2的ED值分别为（7．2±0．32）m Sv和（4．0±0．98）m Sv，组2比组1下降44％，2组间的辐射剂量差异有统计学意义（t=18．099，P〈0．01）。（2）组1和组2冠状动脉各段图像质量平均评分分别为：（4．41±0．35）分和（4．38±0．37）分，2组之间图像质量评分差异无统计学意义（t=0．343，P〉0．05）。结论128层螺旋CT冠状动脉造影检查时合理运用EGG—pulsing及CAREDose 4D技术可大幅度降低辐射剂量且不影响图像质量。

Study on reducing radiation dose with electrocardiogram -pulsing and CAREDose 4D technique in 128 -slice spiral CT coronary angiography

Objective To evaluate the value of reducing radiation dose and image quality with ECG - pulsing and CAREDose 4D technique in 128 - slice spiral CT coronary angiography. Methods Sixty - eight consecutive patients whose heart rates were less than 75 beat per minute and cardiac rhythm was regular were randomly divided into two groups. Conventional technique of CT coronary angiography was employed in group 1 ,while ECG - pulsing and CAREDose 4D technique was applied in group 2. Dose length product（DLP） were obtained automatically, and then the corresponding effective dose （ED） were calculated. The quality scores were performed on obtained imaging by using double blind method. Student t - test was applied in the comparison of value of ED and quality of imaging between two groups. Results The value of ED was （ 7.2 ± 0. 32 ） and （4. 0 ± 0. 98 ） mSv in group 1 and group 2, respectively, which reached statistically significant differences between the groups （ t = 18. 099 ,P 〈0. 01 ）. The quality scores of coronary images were （4. 41 ± 0. 35 ） and （4.38 ± 0. 37 ） in the groups, which did not reach the statistical significance（ t = 0. 343, P 〉 0.05 ）. Conclusion The proper application of ECG - Pulsing and CAREDose 4D technique in 128 - slice spiral CT coronary angiography can reduce radiation dose significantly while having not influence on the quality of the imaging.