双源CT冠状动脉成像在早搏患者中应用的初步体会

Dual-source CT coronary angiography in patients with premature heart-beats： initial experience

目的探讨应用双源CT对早搏患者进行冠状动脉成像的可行性。方法对70例临床可疑冠心病的早搏患者进行双源CT增强扫描。利用回顾性心电门控重建心电图编辑前后的图像，以4级记分评价图像质量。比较心电图编辑前后的图像质量采用配对t检验。结果70例中28例患者的心率波动范围较小[（41．0±18．4）次／min]，无需心电图编辑可获得诊断级图像；其余42例患者的心率波动范围较大[（71．4±28．7）次／min]，心电图编辑前后的冠状动脉图像质量评分分别为（2．09±1．27）和（1．50±0．79）分，差异有统计学意义（t=13．764，P〈0．01）；不可评价的冠状动脉节段比例从24．8％（154／620）降至3．4％（21／620），差异有统计学意义（χ^2=121．846，P〈0．01）。70例患者98．0％（1014／1035）的冠状动脉节段可以评价。结论拥有高时间分辨率的双源CT能够为早搏患者提供可评价的图像；对于心率波动范围大的患者，心电图编辑能够显著改善图像质量。

Objective To evaluate the feasibility of dual-source computed tomography （DSCT） coronary angiography in a population with premature heart-beats. Methods Seventy patients with suspected coronary artery disease and premature heart-beats were routinely imaged on a DSCT scanner （Somatom Definition, Siemens AG, Germany）. The images were reconstructed before and after ECG editing. Two readers independendy assessed image quality of all coronary segments using a four-point grading scale from excellent （ 1 ） to non-assessable （4）. The results of the two groups were compared with a paired t-test, and a P value of less than 0. 05 was considered significant. Results The mean heart rate during examination ranged from 49 to 111 bpm[ mean（70. 7 ± 12.4） bpm]. Twenty-eight of 70 patients with relatively small variability of the heart rate [ （41.0 ± 18.4） bpm] got diagnostic image quality without ECG editing. In other 42 patients with larger variability of the heart rate [ （71.4 ± 28. 7） bpm], the mean image quality scores were 2. 09 ± 1.27 and 1.50 ± 0. 79 before and after ECG editing, there was a significant difference （ t = 13. 764 ,P 〈 0.01 ）. The proportion of non-assessable segments was reduced from 24. 8% （154/620） to 3.4% （21/620） through ECG editing （ X2 = 121. 846, P 〈 0. 01 ）. Finally, the diagnostic image accounted 98.0% （ 1014/1035 ） in all segments of 70 patients. Conclusion DSCT can provide diagnostic images for patients with premature heart-beats. The image quality in patients with larger variability of the heart rate can be significantly improved through ECG editing.