低剂量对比剂320排CT冠状动脉成像可行性研究

Feasibility of low dose contrast material administration in CT coronary angiography using 320-detector CT scanner

目的:探讨单次心跳内采集数据320排CT冠状动脉成像时低对比剂用量的可行性。方法:将131例行冠状动脉CTA检查的病例分为3组,A组对比剂剂量为0.8ml/kg,注射流率4.5ml/s;B组对比剂剂量0.7ml/kg,注射流率5.0ml/s;C组对比剂剂量0.6ml/kg,注射流率5.5ml/s。所有病例心率均<70次/分,单心跳采集心脏数据。分别在主肺动脉干、升主动脉、右冠状动脉和左冠状动脉主干内选择相同的兴趣区测量其CT值,采用单因素方差分析比较3组病例动脉强化程度的差异。结果:C组主肺动脉干CT值为(185.40±46.74)HU,强化程度最低,与A组和B组[分别为(225.77±79.69)和(216.79±51.06)HU]间差异有统计学意义(P<0.05);各组之间升主动脉、右冠状动脉和左冠状动脉主干强化程度差异无统计学意义(P>0.05)。结论:320排CT冠状动脉成像能显著降低单心跳扫描患者对比剂用量,并保证冠状动脉足够程度的强化。

Objective：To study the feasibility of low dose contrast material administration in CT coronary angiography （CTCA） using 320-detector CT scanner for patients with heart rate （HR） below 70 beats per minute （bpm）. Methods： A total of one hundred and thirty one patients planned to do CTCA were enrolled in the study and divided into 3 groups. The volume of contrast used in group A was 0.8ml/kg with the flow rate as 4.5ml/s,in group B was 0.7ml/kg and 5.0ml/s of flow rate,in group C was 0.6ml/kg and 5.5ml/s of flow rate respectively. All of the patients had HR 〈70bpm. The data were acquired within a single heart beat. The CT value of pulmonary artery trunk, ascending aorta, right coronary artery,left main coronary artery were measured and served as region of interest （ROD to compare the degree of enhancement among these three groups. One-Way ANOVA was used to calculate the differences of attenuation value. Results： The CT value in the ROI of pulmonary artery trunk of group C was the lowest （mean, 185.40 ± 46.74）HU, there was significant difference between group C and group A （mean,225.77±79.69）HU and group B （mean,216.79±51.06）HU （P〈0.05）. No significant difference was noted regarding to the ROI of ascending aorta, right coronary artery and left main coronary artery in these three groups （P〉0.05）. Conclusion： Volume of contrast material can be significantly reduced in CTCA using 320-detector CT scanner for the patients with heart rate below 70 bpm.