国产新型320排CT冠状动脉成像的初步应用研究及图像质量评价

目的：我国自主研发的首台320排640层螺旋CT进入临床应用，本研究应用该新型CT进行冠状动脉血管造影检查，初步评估其在不同心率和心律条件下的成像质量和辐射剂量。方法：2020年5月11日至2020年6月19日共160名患者在该型CT行冠脉CT检查。将心律正常者分为低心律组、中等心率组、高心率组，心律不齐者归为心律不齐组。由2名有经验的放射科医师对冠脉CT图像质量进行4级评分，依据分数判定优良，统计图像优秀率及优良率。分析不同心律及心率条件下冠脉近段、中段、远段的图像质量分布。结果：正常心率患者129例（低心率组：40例；中等心率组：57例；高心率组 32例）以及17例心律不齐患者纳入本研究，可评估的冠状动脉血管共计1929段，可诊断率为99.79%，冠脉节段总体优秀率为47.0%，优良率为88.9%。四组患者冠脉图像的总体优良率分别为88.4%、89.4%、88.4%、89.7%，各组间无明显统计学差异（P=0.906）；优秀率分别为48.2%、50.1%、45.8%、36.3%（P=0.004），其中心律不齐组的优秀率明显低于低心率组、中等心率组（P值分别为0.003、0.001）。随着冠脉分支由近及远，图像质量的优秀率和优良率呈明显下降趋势。结论：该新型320排640层螺旋CT在不同心率及心律条件下均可获得满足临床诊断需求的图像,患者个体相关的心律及心率因素对冠脉图像的整体优良率无影响。

Application and image quality evaluation of new domestic 320-slice CT in coronary artery imaging

Objective: The first 320-slice spiral CT independently developed in China had been approved for clinical application. In this study, this new CT equipment was used for coronary angiography, and the imaging quality and radiation dose were preliminarily evaluated under different heart rates and cardiac rhythms conditions. Methods: From May 11, 2020 to June 19, 2020, a total of 160 patients underwent coronary CT examination in this type of CT. The patients with regular heart rhythm were divided into low heart rate group, medium heart rate group and high heart rate group, and arrhythmias were classified as arrhythmia group. The image quality of coronary arteries was graded by two experienced radiologists at grade 4, and the excellent rate and good rate of the images were calculated according to the score. The image quality distribution of the proximal, middle and distal segments of the coronary arteries under different heart rates and heart rates were analyzed. Results: 129 patients with normal heart rate (Low heart rate group: 40 cases; Medium heart rate group: 57 cases; High heart rate group:32 patients) and 17 patients with arrhythmia were included in this study. There were 1,929 coronary artery segments were evaluated, and the diagnostic rate was 99.79%. The overall excellent rate of coronary segments was 47.0%, and the good rate was 88.9%. The overall excellent and good rates of coronary artery images in the four groups were 88.4%, 89.4%, 88.4% and 89.7%, respectively, with no statistically significant difference between the groups (P=0.906). The excellent rates were 48.2%, 50.1%, 45.8% and 36.3% (P=0.004), respectively, and the excellent rates in the arrhythmia group were significantly lower than those in the low heart rate group and the moderate heart rate group (P=0.003, 0.001 respectively). With the coronary artery branches from proximal to distal, the excellent rate and good rate of image quality decrease obviously. Conclusion: The new 320-slice spiral CT can obtain images that meet clinical diagnostic requirements under different heart rates and heart rate conditions, and the factors of cardiac rhythm and heart rate have no influence on the overall good performance of coronary images.