Clinical application of 64-slices volume CT pulmonary angiography with low dose contrast media

Objective To evaluate the clinical application of 64-slices volume CT pulmonary angiography with low dose contrast media.Methods Fifty patients with suspected pulmonary embolism and normal heart functions scheduled for 64-slices volume CT pulmonary angiography were randomly assigned to use regular dose of contrast media(80 ml) or low dose(40 ml),with 25 patients in each group.The identical CT scanning parameter was used in both groups,and the non-ion contrast agent iohexol with the concentration of 370 mgl/ml was injected with the flow rate of 4 ml/s.The images were evaluated and analyzed by two experienced radiologists independently.The image quality was evaluated with 5-grade standard,the CT density subtraction of pulmonary artery and the adjacent pulmonary vein were also measured.Results All pulmonary artery trunk and the major branches in both groups were well delineated.There was significant difference in CT density subtraction of pulmonary artery and the adjacent pulmonary vein between the two groups.The image quality scores of regular dosage group were rated 5 in 8 cases,4 in 11,3 in 6,and those of low dosage group were rated 5 in 7 cases,4 in 13,3 in 5.There was no statistical difference in image quality between two groups.Conclusion Low dose contrast media can be used in 64-slices volume CT pulmonary angiography to diagnose pulmonary embolism accurately with reduced toxicity of contrast media,which is of high value in clinical application.