第3代双源CT大螺距70kV管电压15ml对比剂用量模式在CT肺动脉成像中的应用

发布时间：2019-01-14 16:59

【摘要】：目的评估第3代双源CT大螺距70 kV管电压15 ml对比剂用量模式在CT肺动脉成像(CTPA)中的应用价值。方法将70例临床拟诊肺栓塞行CTPA检查的患者随机分为2组:(1)A组(n=35)行常规CTPA扫描模式(120 kV,80 ml对比剂);(2)B组(n=35)行大螺距70 kV管电压15 ml对比剂用量模式。测量所有患者的肺动脉主干、右肺上叶尖段肺动脉、右肺下叶后基底段肺动脉、胸前空气及背部肌肉的CT值及标准差,计算图像信噪比(SNR)、对比噪声比(CNR)和每例患者的有效剂量(ED)。由2名医师共同对肺动脉图像进行主观评分,两组图像质量的比较采用独立样本的非参数等级检验,并计算Kappa(κ)值评价2名医师对两组间图像质量评分的一致性。采用独立样本t检验分析两组间CT值、SNR、CNR和ED值的差异是否具有统计学意义。结果 A、B两组患者在肺动脉主干[(300.62±77.54)HU比(332.80±102.80)HU;t=-1.53,P=0.13]、右肺上叶尖段肺动脉[(361.72±84.92)HU比(325.37±87.86)HU;t=1.81,P=0.08]和右肺下叶后基底段肺动脉CT值[(359.54±89.61)HU比(318.26±87.19)HU;t=2.00,P=0.05]方面差异均无统计学意义。A组图像右肺上叶尖段(22.81±6.05比19.80±6.60;t=2.05,P=0.04)及右肺下叶后基底段肺动脉(22.65±6.37比19.28±6.63;t=2.23,P=0.03)CNR均明显高于B组。A、B两组图像主观质量评分分别为1(1,1)、1(1,1),差异无统计学意义(Z=-0.08,P=0.93)。两位医师分析图像质量的一致性非常好(κ=0.87,P=0.01)。A组的ED为(4.33±1.80)m Sv,明显高于B组的(0.92±0.23)m Sv(t=11.72,P=0.00),B组的ED值较A组降低了约79%。结论第3代双源CT在大螺距70 kV管电压15 ml对比剂模式下行CTPA检查,可获得满足诊断需求的图像并大幅度降低辐射剂量。
[Abstract]:Objective to evaluate the application value of the third generation dual-source CT with large pitch 70 kV tube voltage of 15 ml contrast medium in CT pulmonary artery imaging (CTPA). Methods 70 patients with pulmonary embolism were randomly divided into two groups: (1) A group (n = 35) underwent routine CTPA scan (120 kV,80 ml contrast agent); (2) Group B (NM35) was given a large pitch 70 kV tube voltage of 15 ml. The CT values and standard deviations of pulmonary trunk, apical segment of right lung, pulmonary artery of posterior basal segment of right lower lobe, chest air and back muscle of all patients were measured. The signal-to-noise ratio (SNR) (SNR), was calculated. Contrast noise ratio (CNR) and effective dose (ED). For each patient The pulmonary artery images were evaluated by two physicians. The image quality of the two groups was compared with the non-parametric grade test of independent samples, and the Kappa (魏) value was calculated to evaluate the consistency of the image quality scores between the two groups. The difference of CT, SNR,CNR and ED between the two groups was analyzed by t test. Results the pulmonary artery trunk [(300.62 卤77.54) HU vs (332.80 卤102.80) HU;t=-1.53,P=0.13] and the right superior lobar segment pulmonary artery [(361.72 卤84.92) HU vs (325.37 卤87.86) HU;] in group A and B were found in the main pulmonary artery [(300.62 卤77.54) HU vs (332.80 卤102.80) HU;t=-1.53,P=0.13]. CT value of pulmonary artery of posterior basal segment of right lower lobe [(359.54 卤89.61) HU vs (318.26 卤87.19) HU;] There was no significant difference between the two groups (22.81 卤6.05 vs 19.80 卤6.60) and pulmonary artery (22.65 卤6.37 vs 19.28 卤6.63) in the posterior basal segment of the right lower lobe. The subjective quality scores of the two groups were 1 (1 / 1) and 1 (1 / 1), respectively, and there was no significant difference between the two groups (ZP0. 08) (P < 0. 93), the CNR was significantly higher than that of group B (P < 0. 03), and the subjective quality scores of group A and B were 1 (1 / 1) and 1 (1 / 1), respectively. The consistency of image quality between the two physicians was very good (魏 = 0.87P0. 01). A ED was (4. 33 卤1. 80) m Sv,) significantly higher than that of B group (0. 92 卤0. 23) m Sv (t0. 72P0. 00). The ED value of group B was about 79% lower than that of group A. Conclusion the third generation dual-source CT can be used to detect the high pitch 70 kV tube voltage 15 ml contrast medium mode, and the image can be obtained to meet the diagnostic needs and the radiation dose can be greatly reduced.
【作者单位】：中国医学科学院北京协和医学院北京协和医院放射科;
【基金】：卫生公益性行业科研专项项目(201402013)~~
【分类号】：R563.5;R816.4

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