Quantitative Study Of Dual Source CT Dual Energy Technique For Acute Pancreatitis

Objective: To investigate the quantitative study of dual source CT dual energy technique in acute pancreatitis.Methods: Retrospective analysis was performed on 52 patients with acute pancreatitis diagnosed by clinical and imaging department in our hospital from December 2020 to December 2022 who met the inclusion and exclusion criteria,including 36 males and 16 females.In addition,24 patients with normal pancreas were selected as the control group,including 12 males and 12 females.According to the CT imaging results and referring to the CT severity index(CTSI),the severity of all subjects was graded,and 24 patients in the normal control group were classified as group I(CTSI without score).In the case group,24 patients with mild acute pancreatitis(MAP)were classified as Group II(CTSI score 0-3),25 patients with moderate acute pancreatitis(MSAP)and 3 patients with severe acute pancreatitis(SAP)were classified as Group III(CTSI score 4-10).The arterial and venous phase data of 76 subjects were imported into the dual-source CT post-processing workstation,and the corresponding iodine concentration,dual energy index,effective atomic number and electron density were obtained after processing.The parameters of control group and case group were statistically analyzed.The parameters of group II and group III were compared,and the ROC curve was statistically significant to evaluate the diagnostic efficiency.Spearman rank correlation analysis was used.Results:1.There were no significant differences in age and sex between group II and group III(P > 0.05).2.There were significant differences in IC,DEI and Z in arterial phase between control group and case group(P < 0.05),but no significant differences in Rho(P >0.05).There were statistically significant differences in IC and DEI in venous phase between control group and case group(P < 0.05),but no statistically significant differences in Rho and Z(P > 0.05).3.The overall difference of IC,DEI and Z in arterial phase among group I,Group II and Group III was statistically significant(P < 0.05),the difference between pairwise and pairwise was statistically significant(P < 0.05),and the overall difference of Rho among the three groups was not statistically significant(P > 0.05).There was no statistical significance in DEI,Rho and Z in venous phase among groups I,II and III(P > 0.05),but there was statistical significance in IC among the three groups.IC of groups II and III was statistically significant compared with group I(P < 0.05).There was no significant difference in IC between group II and group III(P > 0.05).4.Group I,Group II and group III subtracted the difference of dual energy parameters in the venous phase respectively.The overall difference of IC difference,DEI difference and Z difference in the three groups was statistically significant(P <0.05),and the difference between piniones was statistically significant(P < 0.05),while the overall difference of Rho difference in the three groups was not statistically significant(P > 0.05).5.There were negative correlations between IC,DEI,Z and CTSI grades in arterial stage(r=-0.826,-0.663,-0.793,P < 0.05).IC difference,DEI difference and Z difference in arteriovenous stage were correlated with CTSI grade,showing a medium-high negative correlation(r=-0.684,-0533,-0.641,P < 0.05).6.The areas under the curve were 0.975,0.874 and 0.958,the optimal diagnostic thresholds were 2.55,0.0105 and 8.06,and the specificities were 92.9%,92.8% and85.7%,respectively.The sensitivity was 95.8%,79.2% and 95.8%,the positive likelihood ratio was 13.49,11.00 and 6.70,and the negative likelihood ratio was 0.05,0.22 and 0.06,respectively.The area under the curve was 0.894,0.805 and 0.871,the optimal diagnostic threshold was-1.35,-0.0065 and-0.405,and the specificity was82.1%,78.5% and 78.6%,respectively,for the diagnostic efficacy of IC difference,DEI difference and Z difference in arterial and venous phases.The sensitivities were 91.7%,87.0%,87.5%,positive likelihood ratios were 5.10,4.05,4.09,and negative likelihood ratios were 0.10,0.17,0.16,respectively.7.There was no correlation between Rho and IC and Z(P > 0.05),but positive correlation between Rho and DEI(r=0.302,P < 0.05).There was no correlation between IC and Rho in venous phase(P > 0.05),Rho was positively correlated with DEI and Z(r=0.30,0.354,P < 0.05),and IC in arterial and venous phase was positively correlated with DEI and Z(r=0.928,0.976,P < 0.05)(r=0.805,0.707,P < 0.05),there was a positive correlation between DEI and Z in arterial and venous phases(r=0.920,P< 0.05)(r=0.827,P < 0.05).Conclusion: 1.DSCT dual energy parameters IC,DEI and Z in arterial phase and IC and DEI in venous phase contribute to the differentiation between normal pancreas and acute pancreatitis.2.The DSCT dual energy parameters IC,DEI and Z in arterial stage showed high diagnostic efficacy in the differentiation of MAP and MSAP+SAP,and showed a medium and high negative correlation with CTSI grading.3.DSCT dual energy parameters IC difference,DEI difference and Z difference had high diagnostic efficacy in the differentiation of MAP and MSAP+SAP,and were in medium and high negative correlation with CTSI grading.The DSCT dual energy parameters IC,DEI and Z in arterial and venous phases were correlated with each other in a medium and high positive correlation.