能谱最佳单能量技术降低下肢CTA对比剂用量的可行性

发布时间：2018-05-02 15:15

本文选题：下肢动脉硬化闭塞 + 对比剂　；参考：《东南大学》2017年硕士论文

【摘要】：目的探讨能谱CT最佳单能量成像技术在下肢动脉成像中降低碘对比剂用量的可行性。方法前瞻性的连续选择行下肢CT动脉成像检查患者75例,按扫描方式及对比剂用量分为三组:传统常规剂量组、能谱常规剂量组及能谱低剂量组。传统常规剂量组及能谱常规剂量组均采用2mL/kg的对比剂用量及3.5mL/s的注射速率,扫描方式及重建方法前者采用120kVp、滤波反投影算法(FBP)重建,后者采用能谱模式、50%自适应统计迭代(50%ASiR)重建。能谱低剂量组的对比剂用量及注射速率均降低20%,采用能谱模式及50%ASiR重建。测量三组图像靶血管的CT值,并记录对比噪声比(CNR)、背景噪声(BN)、剂量长度乘积(DLP)、有效辐射剂量(ED)、摄碘量及注射速率,采用单因素方差分析并联合Bonferroni法进行差异性检验。采用Kruskal-Wallis检验对三组图像质量主观评分进行比较分析。结果按排除标准,最终60例患者纳入本研究,三组患者各20例。能谱常规剂量组有着最佳的CT值、CNR及BN(P0.01),但BN与能谱低剂量组相比无统计学差异(P0.05);能谱低剂量组的CT值及CNR除胫前动脉外(P=0.162;P=0.376),均高于传统常规剂量组(P0.05)。两能谱组的ED均显著低于传统组(P0.01),且两能谱组间无统计学差异(P0.05)。此外,能谱低剂量组摄碘量及注射速率均显著低于能谱常规剂量组及传统组(P0.01)。医师1、2对三组图像的主观评分分别为82分、95分、90分和80分、96分、89分,具有统计学差异(H=4.954,P0.01;H=17.726,P0.01),能谱常规剂量组有着最佳的图像质量,能谱低剂量组的图像质量优于传统常规剂量组(P0.05)。结论能谱最佳单能量成像与传统螺旋CT相比,可以提供更好的CNR及图像质量,在保证下肢动脉成像临床诊断的基础上明显降低了辐射剂量,同时个性化减少了对比剂碘的摄入量。
[Abstract]:Objective to study the feasibility of reducing the amount of iodine contrast agent in lower extremity arteriography with the best single energy imaging technique of energy dispersive CT. Methods Seventy-five patients with prospective CT arteriography were divided into three groups: conventional dose group, conventional dose group and low dose group. The conventional dose group and the energy spectrum routine dose group were reconstructed by 2mL/kg contrast agent dosage and 3.5mL/s injection rate. The former was reconstructed by 120kVpfilter backprojection algorithm. The latter is reconstructed by 50% adaptive statistical iteration of energy spectrum mode. The dosage of contrast agent and injection rate of low dose group were decreased by 20%. Energy spectrum mode and 50%ASiR reconstruction were used. The CT values of the target vessels in the three groups were measured, and the contrast noise ratio (CNR), background noise (BNP), dose length product (DLP), effective radiation dose (EDN), iodine uptake and injection rate were recorded. The differences were tested by univariate ANOVA and Bonferroni method. The subjective scores of three groups of image quality were compared and analyzed by Kruskal-Wallis test. Results according to the exclusion criteria, 60 patients were included in the study, 20 patients in each group. The conventional dose group had the best CT value, CNR and BNN P0.01g, but there was no significant difference in BN between the low dose group and the low dose group, and the CT value and CNR in the low dose group were higher than those in the conventional group, except for the anterior tibial artery. Ed of the two groups was significantly lower than that of the traditional group, and there was no statistical difference between the two groups. In addition, the iodine uptake and injection rate in the low dose group were significantly lower than those in the conventional dose group and the traditional group. The subjective scores of the three groups were 82, 95, 90 and 80, respectively, with statistical difference of 4.954 (P 0.01) and 17.726 (P 0.01). The image quality of the low dose group was better than that of the conventional dose group (P 0.05). Conclusion compared with conventional spiral CT, the best energy spectrum single energy imaging can provide better CNR and image quality, and can obviously reduce the radiation dose on the basis of ensuring the clinical diagnosis of lower extremity arterial imaging. At the same time, individualization reduced the iodine intake of contrast agent.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R816.2;R543.5

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