前瞻性单时相扫描联合“三低”方案在冠心病筛查中的应用价值

The application value of prospective single phase scanning combined with low tube voltage,contrast agent flow rate and total iodine dosage in coronary heart disease screening

目的探讨冠状动脉CT血管成像技术(CCTA)前瞻性单时相扫描联合低管电压、对比剂低流率及低用量方案(简称前瞻性“三低”方案)在冠心病筛查中的应用价值。方法招募2019年8~10月进行集中检查符合标准的86例自愿者,按照随机原则分为传统性多时相扫描组(传统组,46例)及前瞻性单时相扫描组(前瞻组,40例)。传统组使用碘帕醇370对比剂,前瞻组使用典迈伦400对比剂。以BMI=25 kg/m2为界限,分别采用80kV(BMI>25 kg/m2,<28 kg/m2)及70kV(BMI<25 kg/m2)管电压,四种不同的固定对比剂用量及流速方案。通过CT值及对比噪声比比较客观图像质量;基于Likert分级评分法进行主观图像质量比较,配对分析两组最终诊断结果的人数构成比差异及有效辐射剂量。结果两组客观图像质量比较差异无统计学意义(P>0.05),前瞻组主观图像质量评分低于传统组,且有1例扫描失败,但整体图像质量能达到诊断要求,两组诊断结果敏感性相似。前瞻组辐射剂量更低,对比剂用量更少,流率更慢(P<0.05)。结论前瞻性“三低”方案存在扫描失败风险,但在保证设备可靠性、受检者心率<80 bpm及BMI<28 kg/m2的前提下,辐射剂量可低至0.4 mSv左右,使CCTA检查范围可扩大至对高危、无症状冠心病人群的体检。

Objective To explore the application value of coronary CTA prospective scanning combined with low tube voltage,contrast flow rate and total iodine dosage in coronary artery disease screening.Methods 86 volunteers met the standard were randomly divided into retrospective multi-phase scanning group(Traditional group,46 cases)and prospective single phase scanning group(Prospective group,40 cases).In the traditional group,Iodophor(370 mgI/ml)was used as the contrast agent,and in the prospective group,Temeran(400 mgI/ml)was used as the contrast agent.Taking the BMI=25kg/m2 as the limit,the voltage of 80kV(BMI>25kg/m2,<28kg/m2)and 70kv(BMI<25kg/m2)tubes were used respectively,and four different schemes of fixed contrast agent dosage and flow rate were adopted.Objective image quality was compared by CT value and contrast noise ratio(CNR);subjective image quality was compared based on Likert grading scoring method,and the difference of population composition ratio and effective radiation dose between the two groups were analyzed.Results There was no significant difference in objective image quality between the two groups.The subjective image quality score of the prospective group was lower than that of the traditional group,and there was one case of scanning failure,but the overall image quality could meet the diagnosis requirements,and the sensitivity of the diagnosis results of the two groups was similar.In the prospective group,the dose of radiation was lower,the dose of contrast medium was less,and the flow rate was slower.Conclusion Prospective single phase scan based on the prospective group has the risk of scanning failure,but on the premise of ensuring the reliability of the equipment,the heart rate of the subject<80bpm and BMI<28kg/m2.The scope of CCTA examination can be extended to the routine physical examination,providing strong support for clinical prevention.