en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;">Background: Prospectively electrocardiography (ECG)-triggered high-pitch spiral coronary computed tomography angiography (CCTA) is a unique scan mode for dual-source CT (DSCT). Our reports aim to compare image quality and radiation dose of CCTA using high-pitch spiral or sequential acquisition mode in patients with low and stable heart rates. Materials and Methods: Patients with low and stable heart rates (HR) (HR &le; 70 beats per minute [bpm]; heart rate variability [HRV] < 10 bpm) were randomly assigned to high-pitch spiral mode (group A; n = 80) or sequential acquisition mode (group B; n = 80). Image quality scores, image noise, effective radiation dose and influencing factors on image quality were assessed. &nbsp;Results: Mean image quality scores were 1.51 &plusmn; 0.32 and 1.70 &plusmn; 0.38 for groups A and B (P < 0.05), respectively. Image noises of the two groups were 19.05&plusmn;4.70 Hu and 27.21&plusmn;8.88 Hu (P < 0.05). Contrast media cost in group A was lower than group B (P < 0.05). No statistical difference was found in the rate of diagnostic patients between the two groups (P = 0.416). The estimated radiation dose of group A was 26.0% reduced compared with group B (0.74 &plusmn; 0.34 mSv vs. 1.00 &plusmn; 0.48 mSv, P < 0.05). Conclusion: In patients with regular and low heart rates, the prospectively high-pitch spiral acquisition mode can reduce radiation dose and contrast media cost while maintaining image quality compared with the prospectively sequential mode.<br> &nbsp;</div> Tomography, X-ray computed, coronary angiography, image quality, radiation dose. 225 233 http://ijrr.com/browse.php?a_code=A-10-1-720&slc_lang=en&sid=1 Y. Zhuang 7900319475328460011447 7900319475328460011447 No Shandong Medical Imaging Research Institute, Shandong University, No. 324, JingWu Road, Jinan 250021, Shandong, China W. Huang 7900319475328460011448 7900319475328460011448 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China Y. Shi 7900319475328460011449 7900319475328460011449 No Digestive Department, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China G. Bo 7900319475328460011450 7900319475328460011450 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China D. Lu 7900319475328460011451 7900319475328460011451 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China J. Zhang 7900319475328460011452 7900319475328460011452 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China D. Kong 7900319475328460011453 7900319475328460011453 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China Y. Shi 7900319475328460011454 7900319475328460011454 No Department of Medical Imaging, Huai’an First People’s Hospital, Affiliated to Nanjing Medical University No.6, Western Beijing Road, Huanyin District, Huai’an 223300, Jiangsu, China B. Wang binwang001@aliyun.com 7900319475328460011455 7900319475328460011455 Yes Binzhou Medical University, No. 346, Guanhai Road, Laishan District, Yantai 264003, Shandong, China