Table 1.

Extracted features by LIFEx

Conventional	SUVmin, SUVmax, SUVmean, SUVstd, SUVpeak, TLG
Histogram based	Skewness, kurtosis, entropy (log 2&10), energy
Shape based	Volume, sphericity, compacity
GLCM	Homogeneity, energy, contrast, correlation, entropy (log 2&10), dissimilarity
GLRLM	SRE, LRE, LGRE, HGRE, SRLGE, SRHGE, LRLGE, LRHGE, GLNU, RLNU, RP
NGLDM	Coarseness, contrast, busyness
GLZLM	SZE, LZE, LGZE, HGZE, SLZLGE, SZHGE, LZLGE, LZHGE, GLNU, ZLNU, ZP

SUV, standard uptake value; TLG, total lesion glycolysis; GLCM, gray-level co-occurrence matrix; GLRLM, gray-level run length matrix; NGLDM, neighborhood gray-level different matrix; GLZLM, gray-level zone length matrix; SRE, short-run emphasis; LRE, long-run emphasis; LGRE, low gray-level run emphasis; HGRE, high gray-level run emphasis; SRLGE, short-run low gray-level emphasis; SRGHE, short-run high gray-level emphasis; LRLGE, long-run low gray-level emphasis; LRHGE. long-run high gray-level emphasis; GLNU, gray-level non-uniformity; RLNU, run length non-uniformity; RP, run percentage; SZE, short-zone emphasis; LZE, long-zone emphasis; LGZE, low gray-level zone emphasis; HGZE, high gray-level zone emphasis; SZLGE, short-zone low gray-level emphasis; SZHGE, short-zone high gray-level emphasis; LZLGE, long-zone low gray-level emphasis; LZHGE, long-zone high gray-level emphasis; ZLNU, zone length non-uniformity; ZP, zone percentage