Fig. 2.

Categories of radiomics features. Radiomics features including shape features, first order features and texture features. a Shape features describe the shape of ROI such as sphericity and volume. b First order features, such as mean value, median value and entropy, are calculated based on the histogram to describe the distribution of individual voxels values, regardless of the spatial relationship. c Texture features quantify the spatial relationship between voxels, which obtained from various matrix types, such as gray level co-occurrence matrix features, gray level run length matrix features, gray level dependence matrix features, gray level size zone matrix features, and neighbouring gray-tone difference matrix features