Study On The Image Quality Of Dual Energy Imaging Of Myocardium By Reducing The Concentration Of Contrast Agent

Objective: Analysis and Discussion on the dual source CT(Dual-Source(CT)dual energy imaging,reduce the application effect of contrast agent concentration in myocardial imaging in the injection scheme.Methods: Collected the clinical suspected of60 cases of coronary heart disease and underwent dual energy CT scan patients were randomly divided into A,B two groups,30 cases in each group,A group using iodine contrast agent for 370mg/ml,B group were treated with iodine contrast agent for320mg/ml underwent dual energy CT scan.The contrast agent 80 ml was injected at5.5ml/s flow rate,the two groups of patients with the remaining parameters.The original image will be scanned by conventional recombinant technology,recombinant A,B two groups of conventional mixed energy images(A1,B1).and with 5kev spacing,reconstructed A,B monochromatic images in twogroups(60,65,70,75,80,85,90kev),A2~A8 group,B2~B8 group.A1~A8 group B1~B8 group were measured,the axial four chamber plane,left ventricular lateral wall and anterior chest wall fat CT value,noise value,calculate the signal-to-noise ratio of two groups left outdoor side wall(Signal Noise,Ratio,SNR),contrast to noise ratio(Contrast Noise Ratio,CNR)A group and B group by using single factor analysis of variance of objective evaluation index,group each other compared with LSD method,the optimum kev.compared with independent sample t test group A mixed energy(A1)and B group(B5)?keV(A5)group and B group keV(B5)the difference between.Results:The use of conventional concentration of contrast agent(iodine370mg/ml)monochromaticenergy myocardial imaging,A2 ~ A8 group left ventricular lateral wall of SNR were higher than group A1 mixed energy(3.2±1.5)increased and the differences were statistically significant(P<0.01),noise(SD)than groupA1(44.4±11.9mixed energy)was significantly lowered(P<0.01),A2~A8 group each other were not statistically significant(P >0.05);A5 group CNR(8.2±2.3),SNR(4.8±1.7)compared with A1 group CNR(5.7±2.5),SNR(3.2±1.5)was higher(P<0.01),and SD(19.2±2.6)was significantly lower than that of A group(P<0.01),75 keV was the best keV.The use of low concentration contrast agent(iodine 320 mg/ml)single energy myocardial imaging,B2~B8 group left ventricular lateral wall of SNR were higher than group B1 mixed energy(3.1 ± 1.5)increased and the differences were statistically significant(P<0.01),noise(SD)than group B1(45.0 ± 12.0)mixed energy reduction and the differences were statistically significant(P<0.01),NO significant differences were found among groups B1~B8(P>0.05).group B5 is one of the best single energy level of Kev,75 keVGroup.B5 noise of left ventricular lateral wall image(22.3±7.2)and A1(44.4±11.9)mixed energy images decreased,and there were significant differences(P < 0.05);the other group B5 left ventricular lateral wall image noise(22.3±7.2)the signal-to-noise ratio(4.1±1.2),contrast to noise ratio(8.2±3.3)compared with the A5 group showed no significant difference(P >0.05).Conclusion: To reduce the concentration of iodine contrast agent 320mg/ml with the best monochromatic energy level of 75 kev for dual energy CT myocardial imaging,can be obtained with conventional iodine contrast agent370mg/ml mixed energy reasonably objective image quality,and can meet the needs of clinical diagnosis.