Additional file 1 of Contrast-enhanced photon-counting detector CT for discriminating local recurrence from postoperative changes after resection of pancreatic ductal adenocarcinoma

Additional file 1: Supplementary Table S1. Comparison of quantitative spectral PCD-CT variables between LTR and POC in dual phase. Supplementary Table S2. Comparison between different logistic regression models for late arterial phase, portal venous phase, and both contrast phases combined, comprising variables that were statistically significant in the univariate analysis and retained non-zero coefficients after LASSO regression. Supplementary Fig. S1. Check of the linearity of the logit assumption for the LAP model (a, b) by plotting the logit of predicted probabilities against the variable NIC (a) and 70 keV (b); and for the PVP model (c, d) by plotting the logit of predicted probabilities against the variable IC (c) and 90 keV (d). The variables from each model demonstrate a satisfactory level of linearity with the logit of predicted probabilities.