Table 2. The features obtained from preprocessing.
| Feature types | Features |
|---|---|
| Shape-based | None |
| First order-based | Skewness |
| Texture-based | gldm_DNUN, gldm_DV, glcm_Imc1, glcm_CS |
| LoG-based | LoG0.5_glcm_MP, LoG0.5_F_Skewness, LoG0.5_glszm_ SZNUN, LoG0.5_ glszm_ SALGLE, LoG1.5_glcm_Imc1, LoG2.5_glcm_Imc1, LoG2.5_ glszm_ LALGLE, LoG2.5_ glszm_ SALGLE |
| Wavelet-based | WHHH_F_Skewness, WHHH_F_Median, WHHH_F_Mean, WHHH_glszm_SAE, WHHH_ngtdm_Strength, WHLL_glcm_CS, WHLL_F_Skewness, WHLL_F_Median, WHLL_F_Kurtosis, WHLL_glszm_ SZNUN, WLHL_F_Skewness, WLHL_glszm_ SZNUN, WLHH_F_Mean, WLHH_glszm_SAE, WLHH_ngtdm_Strength, WLLH_F_Skewness, WLLH_F_Mean, WLLH_glszm_ SZNUN, WLLH_glszm_GLNU, WLLL_glcm_CS, WLLL_glcm_IV, WLLL_F_Mean, WLLL_F_Skewness, WHHL_F_Skewness, WHHL_glszm_ SZNUN, WHLH_F_Mean, WHLH_glcm_IDM, WHLH_glszm_SAE |
gldm, gray-level dependence matrix; DNUN, dependence non-uniformity normalized; DV, dependence variance; glcm, gray-level co-occurrence matrix; Imc1, informal measure of correlation 1; CS, cluster shade; LoG0.5/1.5/2.5, volume preprocessed using Laplacian of Gaussian band pass filter with 0.5/1.5/2.5 filter width; MP, maximum probability; F, first order; glszm, gray-level size-zone matrix; SZNUN, size zone non-uniformity normalized; SALGLE, small area low gray-level emphasis; LALGLE, large area low gray-level emphasis; WHLL, volume with a wavelet high-pass filter along x-direction, a low-pass filter along y-direction and a low-pass filter along z-direction; SAE, small area emphasis; ngtdm, neighboring gray-tone difference matrix; GLNU, gray-level non-uniformity; IV, inverse variance; IDM, inverse difference moment.