能谱CT小剂量对比剂行肺动脉CT血管造影术的可行性研究

Feasibility of low dose contrast agent in computerized tomography pulmonary angiography with spectral CT imaging

目的探讨能谱CT小剂量对比剂团注试验法(test bolus)在肺动脉CT血管造影术(CTA)成像中的可行性。方法收集43例怀疑肺动脉栓塞的患者行肺动脉CTA。按登记号尾数单双数分为研究组23例、对照组20例。研究组采用能谱扫描模式,使用小剂量对比剂团注试验法;对照组使用常规剂量对比剂智能动态跟踪(smartprep)技术。研究组采用最佳对比噪声比(CNR)技术,两组分别测量肺动脉主干及左、右肺动脉干CT值并进行比较。采用5分法对图像质量评分并比较。结果研究组与对照组肺动脉主干CT值分别为(387.92±48.18)Hu、(326.95±48.51)Hu,差异有统计学意义(P=0.000)。左肺动脉干CT值分别为(390.19±57.91)Hu、(341.04±34.95)Hu,差异有统计学意义(P=0.002)。右肺动脉干CT值分别为(398.02±55.35)Hu、(312.15±40.16)Hu,差异有统计学意义(P=0.000)。图像质量评分分别为(4.61±0.66)分、(3.90±1.02)分,差异有统计学意义(P=0.009)。结论能谱CT小剂量对比剂团注试验法肺动脉CTA能够提高图像质量,同时减少对比剂用量。

Objective To discuss the feasibility of test bolus （TB）by using low dose contrast agent with spectral CT imaging in CTPA.Methods 43 patients with suspected pulmonary embolism （PE）underwent CTPA were randomly divided into the study group（n =23）and the control group（n =20）.The study group using spectrum scanning pattern with small dose of contrast agent injection test method.The control group used conventional dose of contrast medium intelligent dynamic tracing （smartprep）technology.The optimal CNR was used in experimental group.The CT values of main pulmonary artery （MPA）,left pulmonary artery （LPA）,and right pulmonary artery （RPA）were measured and compared in the two groups,respectively.The image quality was evaluated and compared with 5-point scale.Result The CT values of MPA in experimental group and control group were （387.923 ± 48.184）Hu,and（326.95 ±48.51）Hu ,respectively.The CT values of LPA in experimental group and control group were （390.19 ±57.91）Hu,and（341.04 ±34.95）Hu,respectively.The CT values of RPA in experimental group and control group were （398.02 ±55.35）Hu,and（312.15 ±40.16）Hu,respectively.The average scores of experimental group and control group were （4.61 ±0.66）and（3.90 ±1.02）respectively.The Differences were statistically signifi-cant（P =0.000,0.002,0.000,0.009 respectively）.Conclusion Energy spectrum CT with small dose of contrast a-gent injection test pulmonary artery CTA may improve the image quality of CTPA and decrease the dose of contrast agent.