Résumé
Objective To explore the feasibility of low-concentration contrast agent and low-dose technology for pulmonary angiography by comparing the image quality and radiation doses to the patient by different tube voltages and concentrations of contrast agents.Methods Totally 60 patients suspected with pulmonary embolism were divided into C, L1 and L2 groups, of which,Group C had the scanning parameters of 120 kV and 350 mgI/ml,Group L1 had the parameters as 100 kV and 350 mgI/ml and Group L2 had the parameters of 100 kV and 270 mgI/ml.The three groups had the tube voltage as 500 mA, the contrast agent dose as 25 ml,physiological saline dose as 40 ml and flow rate as 4.5 ml/s.SPSS 19.0 software was used to compare and analyze the CT values of pulmonary artery segment,superior vena cava and ascending aorta,main pulmonary artery noises,the image quality as well as the radiation doses of volume scanning. Results The three groups had the main pulmonary aortas and their branches display clearly to meet clinical requirements.When compared with Group C,Group L1 had higher CT values of the main pulmonary aorta and its branches,higher image noise while lower radiation dose (P<0.01);Group L2 had equivalent CT values of the main pulmonary aorta and its branches (P>0.05),higher image noise while lower radiation dose (P<0.01).When compared with Group L1,Group L2 had lower CT values of the main pulmonary aorta and its branches (P<0.01),and equivalent image noise and radiation dose (P>0.05).Conclusion Low-concentration contrast agent and low-dose technology gains feasibility and advantages when used in 320-slice CT pulmonary angiography.