Revolution 256CT low dose energy spectrum iodine water-based material pairs and the slope of three segments energy spectrum curve in quantitatively identifying different peripheral lung cancer types

XIAO Huijuan; LIU Yihe; LIANG Pan; HOU Ping; ZHANG Yonggao; YUE Songwei; GAO Jianbo

Abstract：Objective To investigate the value of low dose energy spectrum scanning and the slope of three spectral curves of Revolution 256 CT in quantitative analysis of different peripheral lung cancer.Methods A total of 126 cases of peripheral lung cancer,including adenocarcinoma in 62 cases,squamous cell carcinoma in 49 cases and small cell carcinoma in 15 cases con-firmed by Revolution 256 CT low-dose energy spectrum scanning were retrospectively analyzed.The biphase iodine content and water content,standardized iodine water concentration(NIC,NWC)and the difference of standardized iodine water concentra-tion(ICD,WCD)were measured and calculated.The two-phase energy decay curve was reconstructed,and the decay curve was divided into three intervals of 40～70 keV,70～100 keV and 100～140 keV,and the slope was calculated respectively.One-way analysis of variance was used to compare the differences between multiple groups,and LSD method was used for pairwise comparison when there were differences between groups.P<0.05 meant the difference was statistically significant.Results 1)Biphasic iodine-base value,NIC and ICD were as follows:adenocarcinoma>squamous cell carcinoma>small cell carcinoma,and the differences were statistically significant(F=3.397～6.188,P<0.05).2)The arterial phase water base value and NWCAP-were as follows:squamous cell carcinoma>adenocarcinoma,squamous cell carcinoma>small cell carcinoma(F= 5.017-9.899,P<0.05),with significant differences;but,there was no significant difference between adenocarcinoma and small cell carcinoma.There was no significant difference in water base value,NWCVP and WCD in venous phase of nodules(F=0.341～0.710,P>0.05).and 3)The slope comparison showed that the 40～70 keV segment was as follows:adenocarcinoma>squamous cell carcinoma>small cell carcinoma;For 70～100 keV segment,the result was squamous cell carcinoma>adenocarcinoma>small cell carcinoma;As for 100～140 keV segment,the result was squamous cell carcinoma>adenocarcinoma>small cell car-cinoma;The low energy level of the three groups showed a large difference,while,the high energy level showed a small differ-ence.Small cell carcinoma corresponded to the lowest CT value at single energy.Conclusion Revolution CT spectral quantita-tive parameters are helpful for noninvasive diagnosis of peripheral lung cancer.