TABLE II.

Power Spectrum Models for CT Slice

	3D-3D: CT-to-CT Slice
Signal (Bone) Spectrum	$G\left(f_x,f_y\right)=\left(\frac{{\alpha }_G}{f_0^{{\beta }_G}+f^{{\beta }_G}}+a_G{e}^{-b_{G}f}\right)MT{F}^2$
Soft-Tissue Spectrum	$S_i\left(f_x,f_y\right)=\left(\frac{{\alpha }_S}{f_0^{{\beta }_S}+f^{{\beta }_S}}\right)MT{F}^2$
Quantum Noise	$Q_i\left(f_x,f_y\right)={\alpha }_Q\cdot f\hspace{0.17em}MT{F}^2+c_Q$
MTF	$MTF\left(f_x,f_y\right)=\text{Hann}\left(f_c\right)$