The Evaluation of Quantitative Parameters of Dual-layer spectral detector CT for Discrimination of Differentiation grade, T Stage, and Lymph Node Metastasis stage of Colorectal Adenocarcinoma

Objectives: To investigate the value of quantitative parameters of Dual-layer spectral detector CT (SDCT) in the differentiation grade, T stage, and lymph node metastasis stage of colorectal adenocarcinoma (CRAC). Methods: 86 eligible CRAC patients were included in this study. The conventional CT values, 40 keV values, 100 keV values, effective atomic number (Zeff) values, iodine concentration (IC) values, normalized iodine concentration (NIC) and spectral curve slope (λ) during the arterial phase (AP) and venous phase (VP) of CRAC were compared according to the differentiation grade, T stage, and lymph node metastasis stage. Results: The measured values of the spectral quantitative parameters of the CRAC were consistent within the observer (ICC range 0.791–0.979). The 100kev-AP, RT-VP, 40keV-VP, 100keV-VP, Zeff-VP, IC-VP, λ-VP had significant differences among different grades of CRAC differentiation (P < 0.05). ROC showed the AUCs were 0.620, 0.673, 0.680, 0.708, 0.672, 0.678, 0.682 for 100kev-AP, RT-VP, 40keV-VP, 100keV-VP, Zeff-VP, IC-VP, λ-VP differentiating the well differentiation from moderately and poorly differentiation. CT parameter values showed no statistical difference between T1-2 and T3-4 stage, as well as among lymph node metastasis stages of CRAC (P > 0.05). Conclusion: The quantitative parameters of SDCT had good diagnostic efficacy in differentiating differentiation grades of CRAC, however did not show the value for identifying T stage and lymph node metastasis stage.