关键词: 冠状血管造影术, 多排探测器的计算机断层扫描, Turbo Flash扫描模式, 图像质量, 辐射剂量

Abstract: Objective　To investigate the image quality and radiation dose of computed tomography coronary angiography（CTCA） based on a 3rd generation dual-source SOMATOM Force CT（Force CT） and high-pitch Turbo Flash scan mode when being used in patients with different heart rate（HR）.Methods　A total of 98 patients who underwent CTCA at Zhejiang Hospital between August and November 2016 were selected for this study.The patients were divided into three groups according to the HR during the CTCA scan：A group（HR≤65 beats/min，47 cases），B group（65 beats/min<HR≤75 beats/min，24 cases），and C group（HR>75 beats/min，27 cases）．The patients in all three groups were scanned using Force CT and the high-pitch Turbo Flash scan mode.The image quality of various segments of the coronary artery in the three groups was scored subjectively.The dose-length product（DLP） and effective radiation dose（ED） of each group were recorded and compared.Results　The images of 1 443 coronary segments were obtained and evaluated.There were 1 291 segments（89.47%） that scored 1 point for image quality，149 segments（10.33%） had 2 point image quality，and 3 segments（0.20%） scored 3 points for image quality.Gender had no significant effect on HR，image quality，DLP and ED（P>0.05）．The average DLP of the patients was（51.3±12.8） mGy?cm and the average ED was（0.72±0.18） mSv.There were significant differences in the image quality，DLP，and ED among the three groups（P<0.05）．The image quality scores of the B and C groups were higher than the A group（P<0.05），while the DLP and ED of the C group were higher than the A and B groups（P<0.05）．Conclusion　The CTCA based on Force CT and the high-pitch Turbo Flash scan mode has clinical application value for patients with different HR，particularly for patients with HR≤65 beats/min.The appropriate acquisition phase is chosen according to the patient's HR and the images meeting diagnostic requirements can be obtained.Moreover，the effective radiation dose can be < 1 mSv.

Key words: Coronary angiography, Multidetector computed tomography, Turbo Flash scan mode, Image quality, Radiation dosage