Table 1.

Intensity and First-Order Image Features

Feature	Description
Imin	Minimum intensity value in the 3D ROI
Imax	Maximum intensity value in the ROI
Imean	Mean intensity value in the ROI
SD	Variation from the average intensity in the ROI
Skewness	Measure of the symmetry of the intensity distribution
Kurtosis	Measure of the shape of the peak of the intensity distribution
Coeff Var	Normalized measure of the dispersion of the ROI (coefficient of variation)
TGV	Total summed intensity
I30⁎	Intensity ranging from lowest to 30% highest intensity volume
I10-I90⁎	Intensity ranging from lowest to 10% highest intensity volume minus intensity ranging from lowest to 90% highest intensity volume
V40⁎	Percentage volume with at least 40% intensity
V70⁎	Percentage volume with at least 70% intensity
V80⁎	Percentage volume with at least 80% intensity
V10-V90⁎	Percentage volume with at least 10% intensity minus percentage volume with at least 90% intensity
Sphericity	Measure of the spherical shape (roundness) of the ROI
Convexity	Measure of the spiculation of the ROI (ratio of true ROI volume to convex ROI volume)

^⁎Denotes features that were derived from intensity volume histogram [10].