双源CT冠状动脉成像:320mgI/ml替代370mgI/ml对比剂的可行性

Coronary Angiography with Dual-source CT: A Feasibility Study to Replace 370 mgI/ml with 320 mgI/ml Contrast Medium

目的比较320 mg I/ml及370 mg I/ml两种不同浓度碘对比剂对双源冠状动脉CT血管成像(CCTA)图像质量的影响,探讨CCTA中较低浓度对比剂替代高浓度对比剂的可行性。资料与方法 100例临床拟诊为冠状动脉疾病患者随机分为两组,两组患者体重指数相当,高浓度组对比剂采用370 mg I/ml碘普罗胺,注射流速5.0 ml/s;低浓度组对比剂采用320 mg I/ml碘佛醇,注射流速5.8 ml/s;两组碘流速均为1.85 g I/s,碘负荷均为0.34 g/kg。测量升主动脉及降主动脉的CT值及右冠状动脉近段、右冠状动脉远段、左主干、前降支及左回旋支的信噪比和对比噪声比,并采用4分法进行图像质量主观评价。结果两组升主动脉及降主动脉的强化CT值差异均无统计学意义(P>0.05);两组右冠状动脉近段、右冠状动脉远段、左冠状动脉主干、左前降支、左回旋支的信噪比及对比噪声比差异均无统计学意义(P>0.05);2名评估者对图像质量评分一致性较好(Kappa=0.773,P<0.05),两组图像质量主观评分差异无统计学意义(Z=0.117,P>0.05)。结论在双源CCTA中,保持碘流速和总碘负荷一致,320 mg I/ml及370 mg I/ml两种不同浓度对比剂所得图像质量相似,320 mg I/ml可以替代370 mg I/ml对比剂。

Purpose To compare impact of two different concentrations of iodine contrast agent（320 mg I/ml and 370 mg I/ml） on image quality of dual-source CT coronary angiography（CCTA）, and to investigate the feasibility to replace higher concentrations with lower concentration contrast medium in CCTA. Materials and Methods 100 patients were randomly divided into two groups, and no difference of BMI was found between two groups, iopromide of 370 mg I/ml was used in group A with flow rate of 5.0 ml/s, while iodixanol of 320 mg I/ml in group B with flow rate of 5.8 ml/s, iodine delivery rate（1.85 g I/s） and total iodine load（0.34 g/kg） of the two groups were the same. The CT values of the ascending aorta and descending aorta, signal-to-noise ratio（SNR） and contrast-to-noise ratio（CNR） of 5 main points（right coronary artery proximal, right coronary artery distal, left main, left anterior descending branch and the left circumflex branch） of coronary artery were measured, and the four-point method was used for subjective assessment of image quality. Results No statistical significant difference between the two groups was found in CT value of ascending aorta and descending aorta（P〉0.05）, SNR and CNR in right coronary artery proximal, right coronary artery distal, left main, left anterior descending branch and the left circumflex branch（P〉0.05）. The consistency of the image quality score between the two evaluators was good（Kappa=0.773, P〈0.05）, there were no statistical significance of subjective image quality scores between the two groups（Z=0.117, P〉0.05）. Conclusion Keeping similar iodine deliver rate and total iodine load, similar image quality can be got from 320 mg I/ml and 370 mg I/ml contrast medium, and the former can substitute for the latter in dual source CCTA.