Feasibility Of Coronary CTA Scanning Using Low Tube Voltage And Contrast Medium Dose With High Concentration

CT intravascular contrast medium has been widely applied in clinical practice.However,there are some misapplications in clinical use of contrast medium for many young radiologists don' t have fully understanding of their basic knowledge.In our article,classifications of the contrast agents,as well as their physical and chemical characteristics and the influencing factors,are fully stated by refer to the related literatures and combine with some radiologists' clinical experiences for years.Meanwhile the related factors that involve the kidney security and how to truly reduce nephrotoxicity are also analysed.We made some experiments in order to enhance the understanding of high-concentration contrast agent and the particular use of contrast agent in portal vein enhancement.We hope that radiologists could meet somewhat help from our article.PurposeTo determine whether high concentration contrast medium could be used to coronary CTA with low tube voltage and iodine dose.Materials and Methods60 patients were randomly divided into two groups(30 for each):,Group A,400mgI/ml iodinated contrast agent,100kv,210mgI/kg;and reconstructed with iterative reconstruction(IR);group B,350mgl/ml iodinated contrast agent,120 kv,280mgI/kg and reconstructed with filtered back projection(FBP).The CT attenuation values of aortic root(AR),left main coronary artery(LMA),right main coronary artery(RMA),left circumflex artery(LCX)and chest wall muscle tissue were measured.The CT dose index-volume(CTDI),Signal-to-noise ratio(SNR),and contrast-to-noise ratio(CNR)were measured and statistically analysed.Image quality were evaluated by two senior radiologists using a qualitative five-point scale.ResultsCompared with group B,group A significantly reduced the iodine intake(A:15.0±1.54g,B:19.7±3.0g,P<0.01)and injection rate(A3.4±0.35ml/s,B:5.1±0.78ml/s,P<0.01).The radiation dose of group A was reduced by about48.5%(A:6.45±1.07mSv,B:12.53±2.27mSv,P<0.01).CT attenuation value,SNR and CNR of all segments had no significant differences(P>0.05)but SNR of RCA.Group A and B had similar image quality(P<0.01).ConclusionUnder the premise of image quality,high concentration CM(400mgI/ml)combined with 100kv,25%iodine intake reduction and IR has significant advantages over conventional protocol.