Feasibility Of Low Dose Iso-osmolar Contrast Media In 640-slice Volume CT Coronary Angiography

Coronary heart disease?coronary heart diseases,CHD?as a kind of common diseases in the elderly,is common throughout the world.As a populous country,China,the trend of population aging increases year by year,CHD events in middle-aged and old people in China is also more and more common,with the improvement of quality of life and the work pressure increases.However,it also often occurs in young adults.To find the early signs of CHD timely,a higher-end imaging equipment is indispensable,Toshiba 320-row 640-slice volume CT was born,it has a160 mm wide detector,which can cover cardiac at one time scan,and is currently a noninvasive method of screening for higher CHD values and has lower radiation dose.In order to reduce the CHD further,patients receive contrast agent dosage.It works when the injection of contrast material has adverse impact on patients'body,and reduce the concentration of iodine contrast agent at the same time,Among them iso-osmolar contrast media iodixanol is applied to clinical,bringing the gospel to the patients with CHD.This article is to evaluate the effect of iso-osmolar contrast media iodixanol with low dose in coronary CT angiography with 640-slice volume CT.First of all,according to contrast medium using different doses on the 146 patients who suffer from coronary CTA examination of A study,this study is divided into three groups:group a:contrast agent 0.6 ml/kg,64 cases;group b:0.7 ml/kg,45 cases;group c:0.8 ml/kg,37 cases.Then according to the 86 patients who undergo coronary CTA examination of tube voltage and different dosage of contrast agent as B study was divided into two groups:group a:100k V,contrast agent 0.6ml/kg,41 cases;Group b:120k V,0.7 ml/kg,45 cases.Objective evaluation:measuring CT value and noise value of 15segmental coronary arteries and aorta root for each patients,and according to the formula,the section is calculated for each vascular segment of the signal to noise ratio?SNR?and contrast to noise ratio?CNR?;Firstly,Transmit data to the Vitrea postprocessing workstation and to calculate the SNR and CNR of measuring parts.The result is seen as the objective evaluation of the image quality.Subjective evaluation:according to the five points evaluation method,two imaging diagnostic physician evaluate the image quality score.If two physician ratings cannot agree with each other,another diagnosis physician will evaluate high qualification again.Then the result is as subjective evaluation of the image quality.The radiation dose for each patient was recorded.And finally,application SPSS17.0software for data input and statisticsanalysis.The results shows that the study A:CT value in group a was slightly lower than in group b and group c?P<0.05?,while the CT values of each vascular segment section were larger than 250 HU in group a,which is able to meet the diagnostic requirements.SNR and CNR:the SNR and CNR of RCA_p,RCA_m,RCA_d,PDA,LAD-D1,LAD-D2,LCX-OM1,LCX_m,LCX_d in group a were significantly higher than in group b and group c?P<0.05?;The CNR of LM,LAD_p,LAD_m,LAD_d in group were significantly higher than that in group b and group c?P<0.05?;The SNR and CNR of AA were lower than that in group b and group c?P<0.05?;The SNR of LAD_p in group a was lower than that in group b,but significantly higher than that in group c?P<0.05?.However,the SNR of LM,LAD_m,LAD_d,LCX_pwere not statisticatly significant different?P>0.05?.The image quality subjective scoring and radiation dose had no significant difference?P>0.05?.Study B:The CT values of AA,LM,LAD-D1,LAD-D2,LCX_p and LCX_d in group a were significantly higher than that in group b?P<0.05?,the CT values of the remaining coronary vascular segments were of no statisticatly significant difference in two groups?P>0.05?,while the CT values of each vascular segment section were larger than250 HU in group a,which was able to meet the diagnostic requirements.SNR and CNR:the SNR of PDA,LAD-D1,LAD-D2 in group a were significantly higher than group b?P<0.05?,the SNR of the remaining coronary vascular segments was notstatisticatly significant different from the two groups?P>0.05?;The CNR of LAD-D1 in group a was significantly higher than in group b?P<0.05?,the CNR of the remaining coronary vascular segments were notstatisticatly significant difference in the two groups?P>0.05?.The radiation dose between two groups was statisticatly significant different?P<0.05?,with the radiation dose in group a 30%lower than group b.Therefore,the application of 120k V,iodixanol 320mg I/ml and the volume of 0.6 ml/kg by 640-slice volume CT coronary CT angiography,can help get better coronary artery image quality,and greatly reduce the amount of contrast material and the incidence of adverse events of contrast agent,while the image quality can meet the requirements of clinical diagnosis.And 100k V,iodixanol 320mg I/ml and the volume of0.6 ml/kg by 640-slice volume CT coronary CT angiography can reduce the radiation dose,the dosage of contrast agent,the incidence of adverse events of contrast agent,and most important,reduce the unnecessary pain the patients suffer in the process of checking.