采用小剂量监测技术研究影响肺动脉CT血管成像效果的个体因素

Study on individual factors affecting effect of pulmonary artery CT angiography with test bolus technology

目的利用小剂量监测技术探讨对比剂到达主肺动脉的达峰时间和峰值与个体因素之间的关系。方法 174例患者以4 m L/s注射对比剂15 m L,注射对比剂后延迟0 s,用Test Bolus技术在气管分叉水平下2 cm同层动态扫描主肺动脉,用灌注软件分析主肺动脉的时间—密度曲线,获得其达峰时间和峰值。采用直线回归分析和多因素逐步回归法分析患者的性别、年龄、身高、体重、心率、收缩压、舒张压、平均动脉压,是否有心脏病、糖尿病或化疗史等因素与对比剂到达主肺动脉的达峰时间和峰值的关系。结果根据患者个体相关因素得出回归方程:达峰时间(s)=6.61+0.04×体重(kg);峰值(Hu)=699.18-1.4×体重(kg)-1.49×身高(cm)-11.22×达峰时间(s)。结论评估患者的个体因素后根据达峰时间和峰值的回归方程可计算出患者行肺动脉CT血管造影时注射对比剂后的延迟时间和峰值。

Objective To study the relationship among the time to peak, the value to peak of contrast agent arriving to the pulmonary artery and individual factors with test bolus technology. Methods 174 cases were injected with contrast agent 15 m L at a rate of 4 m L/s and after 0 s, using test bolus technique dynamically scanned main pulmonary artery 2 cm under the tracheal bifurcation level in the same layer, the peak of time and the corresponding peak value were obtained by the perfusion software. Meanwhile, linear regression analysis and multivariate stepwise regression analysis were used for analyzing the relationships between sex,age, height, weight, heart rate, systolic pressure, diastolic pressure, mean arterial pressure, heart disease, diabetes or chemotherapy history and time to peak, the value to peak of contrast agent arriving to the pulmonary artery. Results Two regression equations, time to peak（s） = 6.61 ＋ 0.04 × body weight（kg） and peak value（Hu）= 699.18-1.4×body height（kg）-1.49×body weight（cm）-11.22×time to peok（s） were obtained, which based on the number of patients’ gender, age, body weight, systolic blood pressure, body weight, heart rate,etc. Conclusion It is available that the appropriate delay time and the peak value after injecting contrast agent for pulmonary artery CT angiography were obtained in according to regression equations.