Clinical Study Of Dual-source CT Low Tube Voltage Combined With Low Concentration Contrast Agent To Optimize Pancreatic Enhancement

Objective:To optimize the clinical study of pancreatic contrast-enhanced CT scan by reducing radiation dose and low concentration contrast agent.Methods:One handrud condidates were enrolled in this research and randomly divided into A and B group.Tourty-two subjects were contained in Group A,the experimental conditions of which were low voltage(100KV)and low concentration contrast agent(270mgI/mL).Contrastly,the voltage and concentration of group B were repectly 120kv and 350mgI/mL.Under the same circumstances,the routine three-phase scans of 100 patients(arterial phase(20-25s),venous phase(35-45s),and delayed phase(180 s))were performed in the period of the examination of pancreatic contrast-enhanced CT scan with siemens dual-source CT and dual-tube high pressure syringe.DLP and ED were obtained by standard algorithm reconstruction.SPSS 22.0 statistical software was used to compare the age,height,weight,BMI,SNR,CNR,and ED between the two groups using the independent sample t-test after normality test and homogeneity of variance test(according to the normal distribution and homogeneity of variance).Gender comparisons between the two groups were performed using the?~2 test.The Mann-Whitney U-test was used to compare the image quality scores between the two observers(groups A and B)and the Kappa test was used to assess the consistency between the two observers.P<0.05 was considered statistically significant.Results:The general data(sex,age,height,weight and body mass index)among two groups were no significant difference(P>0.05).So did the indicators of SNR,CNR in each phrase.Concretely,in arterial phase,the value of SNR among group A and B was 8.50±1.49 VS vs8.52±1.66,P=0.73.The value of CNR was19.84±3.01 vs 18.63±3.07,P=0.92.In venous phase,the value of SNR was 8.39±1.76 vs 9.98±2.07,P=0.58.the value of CNR was18.92±3.26 VS 20.71±3.91,P=0.053.In delayed phase,the value of SNR was7.10±1.41vs7.77±1.15,P=0.79.the value of CNR was18.17±3.43 vs 18.97±3.35,P=0.96.Nevertheless,the value of ED(3.24±0.29)in group A decreased by 38%compared with the value of group B,the differences of which were statistically significant.Two observers image quality scores in group A were 4.17±0.60 and 4.19±0.6.The difference between the scores of the two observers in each group was determined by the rank sum test.The Z value in group A was-0.45,p=0.65,the Z value in group B was-0.76,and p=0.45.The difference was not statistically significant(P>0.05).The consistency of the observer score scale was good(Kappa value was 0.74 in group A and Kappa value in group B was 0.76).Conclusion:By reducing the tube voltage while using low concentrations of contrast agent,not only the image quality could meet the diagnostic requirements,but also reduce the radiation dose and contrast agent dose.Thus,the purpose of optimizing the clinical study of pancreatic contrast-enhanced CT scan by reducing radiation dose and low concentration contrast agent was accomplished.