碘佛醇350造影剂不同注射速率CTPA图像质量分析

CTPA Image Quality Analysis with Different Velocities of Ioversol 350 Contrast

目的评估不同流速碘佛醇(350mg I·m L^(-1))造影剂CT肺动脉造影(CTPA)的图像质量,探讨3.0m L·s^(-1)能否用于CT肺动脉造影。方法纳入临床行CTPA检查的疑似肺栓塞患者120例,按随机数字表法分配到4.0、3.5、3.0m L·s^(-1)组,碘流率分别为1.4、1.225和1.05g I/s。测量肺动脉主干与主动脉、右肺上叶动脉与右上肺静脉及右肺下叶后基底段动脉与右下肺静脉CT值,计算并比较三组患者的肺动脉CT值、肺动脉与肺静脉CT值之比。结果三组患者的肺动脉强化程度、肺动静脉CT值比值、噪声、信噪比(SNR)、对比噪声比(CNR)、CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP)及有效剂量(ED)相比差异均无统计学意义(P均>0.05),主观图像质量评分及上腔静脉周围射束硬化伪影三组相比差异亦无统计学意义(P>0.05)。结论降低注射速率,虽然会降低肺动脉的强化程度,但程度降低较小,图像质量不但能满足诊断需求,而且降低了进入体内的碘流率,可减少造影剂外渗现象。

Objective To assess image quality of CTPA in different iodine flow rate, and to explore whether the 3.0mL· s-1 can be used in CT pulmonary artery angiography. Methods 120 patients with suspected pulmonary embolism were randomly divided into 4.0,3.5,3.0mL·s-1 group and the iodine flow rates were 1.4,1.225 和 1.05g I/s, respectively. The CT value of main pulmonary artery, the right upper lobe and right lower lobe basal segment of the pulmonary artery were measured. One-Way ANOVA was used to calculate and compare the pulmonary artery mean CT values and the pulmonary arteriovenous CT value ratio of the three group velocity. Results Difference of CT value ratio, noise, SNR, CNR, CTDIvol, DLP and ED among three groups showed no significant（P〉0.05） while difference in subjective image quality scores and the beam hardening artifacts among three groups showed no statistically significant （P〉0.05）. Conclusion With decrease of the injection rate, the pulmonary artery enhancement degree were reduced at small degree and the image quality can not only meet the demand of diagnosis, and also reduces the iodine flow rate into the body. This method could reduce the contrast agent extravasation phenomenon.