Study of abdominal CT angiography in low tube voltage setting combined with personalized contrast media application / 中华放射学杂志

ABSTRACT

ObjectiveTo investigate the feasibility of decreasing radiation dose and contrast media dose of abdominal CTA using low tube voltage setting combined with personalized contrast media application.MethodsOne hundred and twenty patients were randomly divided into 3 groups,and there were 40 patients in each group.120 kV tube voltage was used in group A,and 100 kV tube voltage was used in group B and C.Personalized injection flow rate of contrast media which determined according to patient's body mass (injection flow rate =λ × body mass) was used for all groups,and the λ values for group A,B and C were 0.07,0.07 and 0.06 ml · kg-1· s- 1 respectively. CT dose index volume ( CTDIvol ) effective dose(ED) and contrast media dose were evaluated,and these parameters were all analyzed using one-way ANOVA analysis.Image quality of abdominal aorta and branch arteries was rated using a three-point ordinal for all 3 groups,and image quality score was analyzed using Kruskal-Wallis test.ResultsCTDIvol were (8.2±0.8),(6.0 ±1.0) and (6.1 ±1.1)mGy for group A,B and C,ED were (5.2 ±0.8),(3.5 ± 0.7) and ( 3.6 ± 0.6) mSv,and contrast media dose were (72.3 ± 10.3 ),(73.5 ± 11.3 ) and (61.6 ±9.4) ml,respectively.There were significant differences in CTDlvol,ED and contrast media dose among 3 groups ( F =66.094,77.812,15.919 ; P =0.000).Compare with group A,the ED of group B was decreased 32.7％,and the ED and contrast media dose of group C were decreased 30.8％ and 14.8％,respectively.Image quality was rated as excellent,good,and general for 20,19 and 1 patients in group A,25,15 and 0 patients in group B,and 23,17 and 0 patients in group C,respectively.There was no significant difference in image quality score among 3 groups ( x2 =1.492,P =0.474 ).ConclusionsThe radiation dose and contrast media dose can be decreased in abdominal CTA using low tube voltage and personalized contrast media apolication while image quality can be preserved.