Preliminary Study On Energy Spectrum CT Volume Quantitative Analysis To Differentiate The Pathological Types Of Lung Carcinoma

Objective:To explore the value of energy spectrum CT volume quantitative analysis in the differential diagnosis of lung adenocarcinoma(ADC),squamous cell carcinoma(SQCC)and small cell lung cancer(SCLC).And to explore a better imaging technique for preoperative evaluation of pathological types of lung cancer.Methods:The CT images and clinical data of 75 patients with lung cancer confirmed by pathology were analyzed,including 35 patients with ADC,22 patients with SQCC and 18 patients with SCLC.Calcium concentration and effective atomic number(Eff-Z)in plain scan,iodine concentration and water concentration in arterial phase were measured by volumetric and conventional energy spectrum analysis,respectively.ANOVA was used for comparison of multiple groups,and LSD-t test was used for comparison between two groups,and receiver operating characteristic(ROC)curves were analyzed for statistically significant parameters.Results:In the volumetric energy spectrum analysis,the concentration of calcium,Eff-Z and iodine were ADC>SQCC>SCLC,and there were significant differences among them(P<0.05).But the concentration of water were SQCC>SCLC>ADC,there was no significant difference among them(P>0.05).The results of conventional energy spectrum analysis were similar to those of volume spectrum analysis.No matter ADC,SQCC or SCLC,the concentrations of calcium,Eff-Z and water in the volumetric energy spectrum analysis were significantly lower than those in the conventional energy spectrum analysis,there were significant differences in the above parameters between ADC and SQCC(P<0.05),but there was no significant difference in plain scan calcium concentration in SCLC(P>0.05).While the concentrations of iodine in the volumetric energy spectrum analysis were significantly higher than those in the conventional energy spectrum analysis,there was significant difference between SQCC and SCLC(P<0.05)except ADC(P>0.05).ROC curve analysis showed that the area under the curves,sensitivity and specificity of the volumetric energy spectrum analysis parameters for the differential diagnosis of SCLC and non-small cell lung cancer(NSCLC),ADC and SQCC were higher than those of conventional energy spectrum analysis parameters.The optimal thresholds of the concentration of calcium,Eff-Z,iodine and water in the differential diagnosis of SCLC and NSCLC by volumetric energy spectrum analysis and conventional energy spectrum analysis were 5.09 mg/cm~3 and6.63 mg/cm~3,7.76 and 7.79,1.43 mg/cm~3 and 0.83 mg/cm~3,1003.95mg/cm~3 and 1025.08 mg/cm~3,respectively.And the optimal thresholds of the concentration of calcium,Eff-Z,iodine and water in the differential diagnosis of ADC and SQCC by volumetric energy spectrum analysis and conventional energy spectrum analysis were 6.54 mg/cm~3and 6.00 mg/cm~3、7.92 and 7.86、1.24 mg/cm~3 and 1.08 mg/cm~3、1006.50 mg/cm~3 and 1021.41mg/cm~3,respectively.Conclusion:The volume quantitative analysis of energy spectrum CT may be more valuable in the differential diagnosis of ADC,SQCC and SCLC.