. 2018 May;8(4):410–420. doi: 10.21037/qims.2018.05.01

Table 4. Optimal feature set obtained from Wrapper-based feature selection.

Feature type	ANN	KNN
Shape-based	None	None
First order-based	None	None
Texture-based	None	glcm_CS
LoG-based	LoG_2.5_glszm_LALGLE	LoG_2.5_glszm_LALGLE
LoG-based	LoG_0.5_glcm_MP	LoG_2.5_glszm_LALGLE
Wavelet-based	W_LHL_glszm_ SZNUN	W_LHL_glszm_SZNUN
	W_HHL_F_SKewness	W_HHL_F_SKewness
	W_HLL_F_Median
	W_HLL_glcm_CS
	W_LLL_glcm_CS

glcm, gray-level co-occurrence matrix; CS, Cluster Shade; LoG_2.5, volume preprocessed using Laplacian of Gaussian band pass filter with 2.5 filter width; glszm, gray-level size-zone matrix; LALGLE, large area low gray level emphasis; MP, Maximum Probability; SZNUN, size zone non-uniformity normalized; F, first order; W_LHL, volume with a wavelet low-pass filter along x-direction, a high-pass filter along y-direction and a low-pass filter along z-direction; ANN, artificial neural network; KNN, k-nearest neighbor.