高低浓度造影剂不同注射速度的CT肺动脉造影图像质量分析

摘要

Purpose To compare the CTPA image quality by using contrast agent with different concentration at different injection rate so as to provide suitable contrast agent injection for patients.Materials and Methods A total of 346 patients with suspected acute pulmonary embolism who required to undergo CTPA examination were randomly assigned to high (370 mgI/ml) and low (320 mgI/ml) concentration groups,and each group was further divided into six subgroups with different velocity (3.0,3.2,3.4,3.6,3.8 and 4.0 ml/s).The CT value of the main pulmonary artery,right pulmonary upper lobe artery and right lung under leaf posterior basal segmental artery was measured.Results In the high concentration group,there were no significant differences in pulmonary artery average CT value,noise,single to noise ratio (SNR) and contrast to noise ratio (CNR) among the subgroups with different velocity (P＞0.05).In the low concentration group,the difference was not statistically significant in pulmonary artery average CT value (P＞0.05) among the subgroups with different velocity;however,the noise,SNR and CNR of 3.0 ml/s subgroup had significant differences compared with other subgroups (P＜0.05).There was no significant difference in average CT value of pulmonary artery between the subgroups with the same velocity in the two concentration groups (P＞0.05).In addition,except that the noise,SNR and CNR of 3.0 ml/s subgroup showed significant differences with other subgroups either in high concentration group or in low concentration group (P＜0.05),there were no significant differences in the above-mentioned parameters among other subgroups with the same velocity in both groups (P＞0.05).Conclusion Compared with high concentration contrast agent,the image obtained by using low concentration contrast agent shows no difference in pulmonary artery average CT value but with low iodine flow and iodine flow rate,which can reduce the risks of contrast media induced nephropathy (CIN) and contrast agent extravasation.%目的 比较高低浓度造影剂不同注射速度的CT肺动脉造影(CTPA)图像质量,为临床提供造影剂注射方案.资料与方法 收集临床疑似肺栓塞且需要进行CTPA的患者346例,按造影剂浓度分为高浓度组181例(370 mgI/ml)和低浓度组165例(320 mgI/ml),每组再按注射速度分为3.0、3.2、3.4、3.6、3.8、4.0 ml/s组.测量主肺动脉、右肺上叶动脉及右肺下叶后基底段动脉的CT值并计算其平均值.结果 高浓度组不同亚组间肺动脉平均CT值、噪声、信噪比(SNR)及对比噪声比(CNR)比较,差异无统计学意义(P＞0.05).低浓度组不同亚组间肺动脉平均CT值比较,差异无统计学意义(P＞0.05);3.0 ml/s组的噪声、SNR及CNR与其他亚组比较,差异均有统计学意义(P＜0.05).高低浓度组相同流速亚组间肺动脉平均CT值比较,差异无统计学意义(P＞0.05).高低浓度组3.0 ml/s亚组的噪声、SNR及CNR的差异均有统计学意义(P＜0.05),高低浓度组其余亚组间的差异均无统计学意义(P＞0.05).结论 低浓度造影剂联合低流速CTPA图像的肺动脉CT值与高浓度造影剂相比无差异,且进入体内的碘总量及碘流速较低,可降低患者的肾脏及血管负荷,有利于降低造影剂相关肾病及造影剂外渗发生的风险.