Application Value Of Dual-layer Detector Spectral CT In Evaluation Of Metastatic Lymph Nodes In Lung Cancer

Objective:To investigate the application value of dual-detector spectral CT in the evaluation of metastatic lymph nodes in lung cancer by measuring and analyzing quantitative parameters of lymph nodes.Methods:Fifty-five patients with lung cancer undergoging dual-phase enhanced scan with dual-detector spectral CT imaging were selected.Spectral base images(SBI)data were reconstructed,According to pathological findings,one hundred and six lymph nodes were divided into metastatic group and non-metastatic group.Short diameters of lymph nodes,arterial enhancement fraction(AEF),normalized iodine concentration(NIC)and the slope of the spectral Hounsfeld unit curve(?HU)during arterial(AP)and venousphase(VP)were measured and calculated.Differences were tested for statistical significance using the two-sample t test.Receiver operating characteristic(ROC)curveswere drawn to confirm the optimum threshold and diagnostic efficiency.Combined the parameters with the short diameter of the lymph nodes to calculate the combined diagnostic efficiency.Results:Short diameters of lymph nodes,AEF,NIC and ?HU during AP and VP in the two groups all showed significant differences(P< 0.05).Moreover,the optimum diagnostic efficiency of AEF in metastatic lymph nodeswas the largest(AUCAEF =0.884),and its threshold was 86.36%.The sensitivity,specificity were 92.00%?89.29%,respectively.When combined AEF and short diameter,its AUC can be improved to 0.902.Conclusion:Multiple quantitative parameters of DLCT have the higher diagnostic efficiency in differentiating metastatic and non-metastatic lymph nodes.When combined the short diameter of the lymph nodes and quantitative parameters,the accuracy of the diagnosis can be improved,and could be contributated to the clinical preoperative staging.