The Preliminary Study On The Relevance And Value Of Dual Energy CT Imaging With Pathological Classification And Lung Adenocarcinoma

Objective: through multi parameter measurement, such as the morphological features, spectral curve and normalizing iodine concentration(NIC), from undergoing the dual energy CT imaging on the patients with lung adenocarcinoma, we aimed to explore the relevance and value of dual source CT dual energy imaging to the pathological classification of lung adenocarcinoma.Materials and methods:Selected 47 patients conforms to the conditions of lung adenocarcinoma in the First Affiliated Hospital of Guangxi Medical University from December 2013 to December 2015. These patients underwent dual source conventional CT scanning and dual energy contrast-enhanced CT with Germany’s Siemens 64 slice 64 layers Siemens Somatom Definition to obtain the tumor tissue pathology confirmed. Of the total of 47 patients, 29 patients were males and 18 patients were females. The average age of all patients was 57 years old(range, 31-79 years old).There were 8 cases with level I in high differentiation group, 15 cases in levelⅡ in high differentiation group, 24 cases in level Ⅲ in low differentiation group.The dual energy contrast-enhanced CT images were input into Siemens dual source CT dedicated dual-energy software to obtain the iodine distribution image at artery phase and vein phase, and 40-190 kev series single energy image. Sketched the region of interest(ROI) to obtain mass conventional scan, the iodine distribution image CT value at artery phase and vein phase, and 40-190 kev series single energy image. Recorded the iodine concentration of varies of mass at artery phase and vein phase. And calculated NIC of mass in artery and vein phase= the iodine concentration of primary focus/ the iodine concentration of aorta at the same slice.All data were analyzed with SPSS16.0 statistical software, including X2 test on comparison between groups, t-test on comparison between two independent samples, and ROC curve.Results:1.Through comparing the degree of differentiation of lung adenocarcinoma to tumor’s maximum and minimum diameters respectively, we found that the maximum and minimum diameters in low differentiation group were higher than that in high differentiation group, and the difference had statistical significance(P<0.05), suggesting the degree of differentiation of lung adenocarcinoma was associated with the focus size.2. Of the marginal signs in low differentiation group of lung adenocarcinoma, lobulation signs accounted for 70.8%, which is higher than 30.4% in high differentiation group, and the difference had statistical significance(P<0.05). There was no statistical significance on the percentage of short burr signs between the two groups(P>0.05).3. 26.1% of patients in pulmonary high differentiation group of lung adenocarcinoma were accompanied by Ground-glass opacity, which is higher than 4.2% in low differentiation group, and the difference had statistical significance(P<0.05).4.30.4% of patients in high differentiation group of lung adenocarcinoma presented Vascular convergence signs, which was higher than 25.0% in low differentiation group, but no statistical significance between groups(P>0.05).5. At artery phase, spectrum curves tendency was similar between low and high differentiation groups of pulmonary adenocarcinoma, and there was no significant statistical difference(P>0.05). At vein phase, there existed significant statistical difference on low energy level(40kev-70kev) between low and high differentiation groups of pulmonary adenocarcinoma, and there existed statistical significance(P<0.05). On high energy level(80kev-190kev), CT value in low differentiation group if lung adenocarcinoma was higher than that in high differentiation group, but the curves in two groups was very similar, there was no significant difference.6. At the artery phase, NIC in high differentiation group of lung adenocarcinoma was lower than that in low differentiation group, but there was no statistically significant difference(P>0.05).At the vein phase, NIC in high differentiation group of lung adenocarcinoma was 0.42±0.12(mg/ml), which was lower than that in low differentiation group which was 0.51±0.10(mg/ml), and there existed statistically significance(P>0.05)7. NIC at vein stage was used to evaluate the diagnosis efficiency of the differentiation degree of lung adenocarcinoma. Then we analyzed the area under the ROC curve, we found the area under the ROC curve was 0.785, and the standard error was 0.073, the 95% confidence interval of the area was(0.642, 0.642). NIC at vein phase was used to determine the statistical significance of the differentiation degree of lung adenocarcinoma. The greater the NIC, the lower the degree of differentiation of lung adenocarcinoma. When NIC > 0.4761, the diagnostic efficacy was highest, the diagnostic sensitivity was 83.3%, the specificity was 78.3%.Conclusion: Dual energy CT imaging is a new imaging model of multi parameters. Lung adenocarcinoma in high and low differentiation groups in CT can spectral imaging has different characteristics, and the single energy image spectrum curve in the low energy level at vein phase(40kev-70kev) could predictable distinguish high differentiation group and low differentiation group. NIC quantitative analysis has certain value in predicting pathological classification of lung adenocarcinoma.