能谱CT低电压低对比剂浓度结合ASIR技术对胆囊动脉图像质量影响的研究

发布时间：2018-06-04 16:27

本文选题：胆囊动脉 + 能谱CT　；参考：《临床放射学杂志》2015年08期

【摘要】：目的评价能谱CT低电压低对比剂浓度结合50%自适应统计迭代重建(ASIR)技术对胆囊动脉图像质量的影响。方法前瞻性研究BMI22 kg/m2的患者共116例,年龄25~90岁,BMI 15.79~21.99 kg/m2,按照扫描电压和对比剂浓度分为低电压低对比剂浓度组(A组)和常规电压高对比剂浓度组(B组)。采用GE Discovery HD 750能谱CT机。A组为低电压80 kV p,50%ASIR技术,NI为14;B组采用120 kV p,NI为10。采用高压注射器于肘静脉注射碘对比剂,A组注射威视派克270 mgI/ml,B组注射欧乃派克350 mgI/ml,剂量均为100 ml,注射流率5 ml/s。对两组数据分别测量胆囊动脉、相同层面竖脊肌的CT值及竖脊肌CT值的标准差。计算胆囊动脉与竖脊肌间的对比噪声比(CNR)和信噪比(SNR)。记录CT剂量指数(CTDI)。对胆囊动脉行容积重建、最大密度投影及曲面重组。分别由两位工作7年及3年的放射科医师独立对两组重建后的图像质量进行评价,采用5分评分标准。采用独立样本t检验分析两组的胆囊动脉CT值、竖脊肌CT值、竖脊肌SD值、胆囊动脉-竖脊肌的CNR、胆囊动脉-竖脊肌的SNR、扫描的CTDI及主观评分,P0.05为差异有统计学意义。两位医师对胆囊动脉的评分主观一致性评估采用Kappa检验。Kappa值0.75为一致性良好,0.40~0.75为一般,0.40为一致性差。结果 A组胆囊动脉的CNR(4.22±2.16)明显高于B组(3.41±1.63)(P=0.036);A组胆囊动脉的SNR(8.31±2.14)明显高于B组(5.41±1.76)(P=0.000)。A组和B组胆囊动脉的评分一致性Kappa值分别为0.809和0.758,一致性良好。A组的CTDI(6.44±1.43)mG y明显低于B组(9.28±2.87)mG y(P=0.000)。A组胆囊动脉图像质量的主观评分为(3.46±1.06)分,高于B组[(2.86±1.08)分]图像质量评分(t=2.272,P=0.023)。结论利用低电压80kV p,采用50%ASIR技术,结合低对比剂浓度能够提高胆囊动脉的图像质量。
[Abstract]:Objective to evaluate the effect of low voltage and low contrast medium concentration on image quality of cholecystic artery in combination with 50% adaptive statistical iterative reconstruction (ASIRR) technique. Methods A prospective study of 116 patients with BMI22 kg/m2 aged 2590 years (15.79 卤21.99 kg / m2) was performed. According to the scanning voltage and concentration of contrast agent, they were divided into two groups: group A with low voltage and low concentration of contrast agent (group A) and group B with high concentration of conventional voltage contrast agent (group B). Using GE Discovery HD 750 energy spectrum CT machine. Group A is low voltage 80 kV pN50 and ASIR technique. The NI of 14B group is 120kV PN NI is 10. A high-pressure injector was used to inject venipuncture 270 mg I / ml / ml group A into the cubital vein. Group B was injected with the dose of 350 mg / ml of onepak, and the injection flow rate was 5 ml / s. The CT value and the standard deviation of the vertical spinal muscle and the cholecystic artery were measured in the two groups. The contrast noise ratio (CNR) and signal-to-noise ratio (SNR) between the gallbladder artery and the vertical spinal muscle were calculated. The dose index of CT was recorded. The gallbladder artery was reconstructed by volume, maximum density projection and curved surface reconstruction. Two radiologists who worked for 7 years and 3 years independently evaluated the image quality of the two groups. The CT value of gallbladder artery, the CT value of vertical spinal muscle, the SD value of vertical spinal muscle, the CNR of cholecystic arterial-erector spinal muscle, the CTDI of cholecystic artery and the subjective score (P0.05) of the two groups were analyzed by t-test. The two physicians evaluated the subjective consistency of the cholecystic artery by using Kappa test. Kappa value was 0.75 as good consistency and 0.400.75 as general 0.40 as poor consistency. Results the CNR(4.22 卤2.16 of gallbladder artery in group A was significantly higher than that in group B (3.41 卤1.63). The SNR(8.31 卤2.14 of gallbladder artery in group A was significantly higher than that in group B (5.41 卤1.76)(P=0.000).A) and group B (Kappa = 0.758). The CTDI(6.44 卤1.43)mG y of group A was significantly lower than that of group B. The subjective score of image quality of gallbladder artery in 9.28 卤2.87)mG y(P=0.000).A group was 3.46 卤1.06). The image quality score of group B was higher than that of group B [2.86 卤1.08]. Conclusion the image quality of gallbladder artery can be improved by using low voltage 80kV pand 50%ASIR technique and low contrast medium concentration.
【作者单位】：大连医科大学附属第一医院放射科;
【分类号】：R816.5;R657.4

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