The Value Of Differental Diagnosis Of Dou Ble Source CT Imaging Of Lung Nodule For Pre-invasive Adenocarcinoma/minimally In Vasive Adenocarcinoma And Invasive Aden Ocarcinma

Objective: By measuring parameters of the morphological signs,single-energy CT values,energy spectrum curves,and standardized iodine concentration,which were obtained from the patients with lung adenocar cinoma who undertook dual-source CT dual-energy imaging,to explore the value of dual-source CT dual-energy imaging in differential diagnosis of pre-invasive adenocarcinoma,minimally adenocarcinoma and invasive a denocarcinoma.Materials and methods: Select the patients with the solitary pulmonar y nodules who had undertook dual source CT of the second generation of64 rows of Siemens Somatom conventional plain scan and dual-energy enhanced scan in the First Affiliated Hospital of Guangxi Medical Univers ity from the time 2017.1 to 2018.12 as a research object.Finally 43 cases were matched the condition.43 consecutive patients(19women,24men;m ean age,57.84years;age range,28~78years).All the patient were confirmed lung adenocarcinoma through pathology of surgical operation.We obtained 43 lesions in total.Among them there are 30 cases of invasive adenocarcinoma(IA).4 cases of pre-invasive adenocarcinoma(allbe adenocarcinoma in situ,AIS)and 9 cases of minimally invasive adenocarcinoma(MIA).According to their pathology result and 2011 international classification,we divide nodular AIS or MIA(n=13)to group A,divide nodular IA to group B.The dual-energy enhanced images obtained by dual-source CT dual-energy scanning were sent to the Dual-Energy software of Siemens dual-source CT to obtain single-energy images and iodine distribution images at artery phase and vein phase.By drawing ROI to record the nodule of plain scan CT value?(40-190kev)single-energy CT value,and iodine concentration.The iodine concentration of all nodular lesions in this study was normalized by aortic iodine concentration.Normalized iodine concentration(NIC)formula: NIC =primary iodine concentration / iodine concentration in the same layer of aorta.All data were analyzed by SPSS l6.0 statistical software,P<0.05 was considered statistically significant.The compare the difference of CT features between two groups were analyzed by Chi-square test.Two independent sample t-test was used to compare the difference of lesion size and CT density between the two groups.Two independent sample t-test compared the CT value under each single energy ?normalized iodine concentration between the two groups.Base on the lesion size,plain CT value,arterial and venous NIC calculated ROC curve,we obtained the diagnostic threshold of the size,CT value and Normalized iodine concentration between pre-invasive lesions/ minimally adenocarcinoma and invasive adenocarcinoma.Results:1.Morphological comparison between A and B groups: Among the 43 lesions in the two groups,the incidence of lobulation,spicution,vacuole sign,and pleural indentation of group B were higher than that of group A.Thedifference between the two groups was statistically significant.(P < 0.05),suggesting that these signs contribute to the diagnosis of invasive adenocarcinoma.2.Comparison of nodule size and plain scan CT value between A and B groups: nodules size and CT value of group B were larger than group A,the difference was statistically significant(P<0.05).Analysis the ROC curve,the threshold of the nodule size and CT value in diagnosing invasive adenocarcinoma are 1.3cm and 14.25 Hu.The sensitivity of size diagnosis was90.0%,the specificity was 69.2%;the diagnostic value of CT was 93.3%,and the specificity was 76.9%.3.The value of the energy spectrum curve in the identification of the two groups: the CT value of the group B in the arterial phase were higher than the CT value of the group A,and their energy spectrum curves were similar.The difference between the two groups was statistically significant(P<0.05).The CT values of group B in venous phase were all higher than those of group A.The difference of CT values in the low energy level(40-100 keV)between the two groups was statistically significant(P<0.05).but the difference of CT values in the high energy level(110~190kev)was not statistically significant(P>0.05).4.The value of standard iodine concentration in the identification of two groups: In arterial phase,the standard iodine concentration of group B0.136±0.037(mg/ml)was higher than that of group A 0.084±0.01(mg/ml),the difference between the two groups was statistically significant(P<0.01).In venous phase,the standard iodine concentration of group B 0.329±0.074(mg/ml)was higher than that of group A 0.179±0.027(mg/ml).The difference between the two groups was statistically significant(P<0.01).5.Diagnosis efficiency of NIC: The ROC curve was analyzed with NIC.The area under the ROC curve of the arterial phase was 0.962,and the standard error was 0.027.The diagnostic efficiency was the highest when NIC> 0.1.The diagnostic sensitivity was 90.0%,and the specificity was 100%.The area under the ROC curve was 0.990 in the venous phase,the standard error was 0.014.The diagnostic efficiency was the best when NIC> 0.223,with a diagnostic sensitivity of 93.3% and a specificity of 100%.Though the two-stage enhanced NIC that difference between A and B group all have statistical significance,it can be inferred from the comparison of the area amount that the venous NIC has the highest accuracy in the diagnosis of pre-invasive/ minimally adenocarcinoma and invasive adenocarcinoma.Conclusion:Dual-source CT dual-energy imaging technology provides us with a new diagnostic model that can identify pulmonary nodules by multiple parameters?quantification,which has important clinical application value.Single-energy image energy spectrum curves at each single energy level in the arterial phase,low energy level in the venous phase(40~100kev)and NIC in the arterial and venous phases can be predictively differentiated from invasive pre-invasive/ minimally adenocarcinoma and invasive adenocarcinoma.