Morphological

Area, A
_{
k
}

n
_{
k
}
dxdy where n
_{
k
} is number of voxels in the kth slice of the ROI, d
_{
x
} and d
_{
y
} represent size of voxels

Perimeter length, P
_{
k
}

b
_{
k
} where b
_{
k
} is number of boundary voxels in the kth slice of the ROI

Compactness in 3D, COMP

\( \frac{S^2}{V_{3 D}} \) where S is the surface and V is the volume, defined as follows: \( s = {\displaystyle \sum_x}{\displaystyle \sum_y}{\displaystyle \sum_z}{b}_{ROI}\left( x, y, z\right){v}_{size} slic{e}_{th} \) where v
_{
size
} is the voxel size, slice
_{
th
} is the slice thickness; and V = n
_{
ROI
}
dxdydz where n
_{
ROI
} is total number of voxels in the ROI

Eccentricity, ECC

\( \frac{\sqrt{a^2{b}^2}}{a} \) where a is the major axle shaft and b is the lower one

Dynamic

Basal signal, BS

Signal intensity before contrast injection

Relative enhancement, RE(t
_{
i
})

\( \frac{SI\left({t}_i\right) BS}{BS} \) where t
_{
i
} is the ith temporal instant

Sum of local differences, SOD

\( SO{D}_p= Pr{e}_p+{\displaystyle \sum_{i=1}^T}\left P o s{t}_p(i) P o s{t}_p\left( i1\right)\right \)
