2.6 Statistical Analysis
Python software (PyRadiomics, v2.1.2) and IBM SPSS Statistics software
(version 23.0, IBM Corp.) were used for statistical analysis. A value of
p<0.05 was meant statistically significant. To assess the
performance of the radiomics features and LR models, the receiver
operating characteristic (ROC) curve was used both in training and
validation set, and the area under the receiver operator characteristic
curve (AUC), sensitivity and specificity were calculated in the two sets
respectively. Delong test was used to compare the diagnostic performance
of LR model, exponential-skewness and squareroot-skewness based on NP
images in both training and validation sets. The Mann–Whitney U-test
was used to determine how the most statistically significant features
distributed in training and validation sets.