冠状动脉CT成像中依据心率调节对比剂用量的可行性  

The feasibility of reduced dose of contrast agent dependent on patients＇ heart rate in coronary CT angiography

作　　者：李剑[1] 石明国[1] 印弘[1] 刘从伟[1] 王栋[1] 王帅[1] 姜文龙[1] 刘豹[1] 吴志斌[1] 郑敏文[1] 

机构地区：[1]第四军医大学西京医院放射科,西安710032

出　　处：《中华放射学杂志》2016年第11期870-873,共4页Chinese Journal of Radiology

摘　　要：目的：探讨冠状动脉CT成像（CCTA）中，依据心率调节对比剂用量实现冠状动脉均一强化的可行性。方法前瞻性纳入临床拟行CCTA检查的77例患者，依据心率将其分为低心率组（44例，心率≤75次/min）和高心率组（33例，心率〉75次/min）。所有患者均行双源CCTA检查，低心率组对比剂注射流率3.8 ml/s，剂量0.7 ml/kg；高心率组注射流率5.0 ml/s，剂量0.9 ml/kg。对图像质量进行客观评价（左冠状动脉、右冠状动脉、主动脉强化CT值以及信噪比和对比噪声比）及主观评分，并观察冠状动脉平均强化CT值的均一性。两组患者间对比剂用量、客观评价指标的比较采用t检验，主观评价指标的比较采用非参数检验Mann-whitney U检验。结果低心率组和高心率组患者的对比剂用量分别为（43±6）、（59±8）ml，差异有统计学意义（t=9.647，P〈0.01）。高心率组冠状动脉CT强化值波动范围大，均一性差；低心率组强化CT值波动范围小，均一性好。两组间的主动脉、左冠状动脉、右冠状动脉强化CT值以及SNR和CNR的差异均无统计学意义（P〉0.05）。高心率组中图像质量评分1、2分者分别为16、17例，低心率组中1、2分者分别为35、9例，两组均无3分者，两组间评分的差异有统计学意义（U=－2.834，P=0.005）。结论在CCTA中依照心率调节对比剂用量切实可行，在不降低冠状动脉的图像质量的前提下，可以减少对比剂用量。Objective To evaluate the feasibility of low dose contrast material administration tailored by patients＇ heart rate （HR） in coronary computed tomography angiography （CCTA） using dual-source CT . Methods A total of seventy-seven patients were prospectively enrolled into this study. According to HR, all subjects were divided into low HR group （Group S, HR≤75 bpm） and high HR group （Group H, HR〉75 bpm） . There was no significant difference in the age and weight between two groups. The injection rate and volume of contrast were 3.8 ml/s and 0.7 ml/kg in Group S; 5.0 ml/s and 0.9 ml/kg in Group H, respectively. The CT values of ascending aorta, right coronary artery, left main coronary artery and the lower epicardial fat were measured and compared between two groups. The imaging noise were measured and signal noise ratio （SNR）, contrast noise ratio （CNR） were also calculated. Furthermore, image quality （ 1 to 3, excellent to non-assessable） was compared between the two groups. The dose of contrast material and objective indexes were analyzed by t test, and the subjective indexes were analyzed using Mann-whitney U test. Results The dose of contrast material was （43±6） ml in Group S and （59±8） ml in Group H, and there was a significant difference between two groups （t=9.647, P〈0.01）. The fluctuation range of CT values in Group H was higer than that of Group S. There was no significant difference in the mean CT attenuation of coronary artery, SNR and CNR between two groups （P〉0.05）.The average subjective image quality score of two groups ranged from 1 to 2 and the distribution of different scores was score 1 （16 vs. 35） and score 2 （17 vs. 9）. There was a significant difference between the two groups （U=-2.834, P=0.005）. Conclusion The injection protocol of contrast material tailored by patients＇ heart rate can significantly reduce contrast material dose without compromising the image quality.

关 键 词：造影剂 冠状动脉 体层摄影术 X线计算机 

分 类 号：R816.2[医药卫生—放射医学]