不同碘流率对肾动脉CTA图像最佳触发阈值的影响

摘要

Objective To evaluate the effect on threshold of triggered angiographic acquisition by different iodine flow rate on renal artery CTA using Smart Prep tracking technique.Methods A total of 420 patients were randomly divided into A-D group with iodine flow rate of 0.90 gI/s,1.11 gI/s,1.20 gI/s,1.48 gI/s on average respectively.And each group were divided 7 subgroups with threshold 140-＜150 HU,150-＜ 160 HU,160-＜ 170 HU,170 ＜180 HU,180 ＜190 HU,190-＜200 HU,200-210 HU respectively.The quality of the images were graded from 1 5 by 2 radiologists.The best image quality subgroups were achieved,and the scores were compared among the best image quality subgroups.Results Image quality of renal CTA in each group were best performed with a threshold of 170-＜ 190 HU,160-＜ 190 HU,170-＜ 180 HU,160-＜ 180 HU respectively.When the threshold were 170-＜180 HU,image quality were good with all iodine flow rate groups.There was no significant difference among the scores of the best image quality subgroups (all P＞0.05).Conclusion Different iodine flow rate with appropriate threshold can acquire better image quality of renal CTA.%目的 利用智能追踪(Smart Prep)技术探讨不同碘流率时肾动脉CTA的最佳触发阈值及其对肾CTA图像质量的影响.方法 随机选择临床需行肾动脉CTA检查的患者420例,利用Smart Prep技术进行扫描.将所有患者随机平均分入A～D组,碘流率分别为0.90、1.11、1.20和1.48 gI/s.每组随机平均分为7个亚组,分别按照不同阈值扫描,各亚组触发阈值分别为140～＜150 HU、150～＜160 HU、160～＜170 HU、170～＜180 HU、180～＜190 HU、190～＜200 HU和200～210 HU.采用5分制评分评价图像质量.分析各组的最佳阈值亚组,并进一步比较各最佳阈值亚组的图像质量的差异.结果 A～D组中,最佳触发扫描阈值范围分别为170～＜190 HU、160～＜190 HU、170～＜180 HU和160～＜180 HU.触发阈值为170～＜180HU时能够满足不同碘流率时肾动脉CTA的成像要求.各最佳阈值亚组间肾动脉CTA图像质量差异无统计学意义.结论 不同碘流率配合最佳扫描触发阈值可获得优良的肾CTA图像.