Table 3. Algorithm variations considered. For each tested algorithm (horizontal row), the indicated variations from baseline () are made.

Algorithm
2D FEM (B)	√		√		√	√	√	√	√	√
NOSER prior (B)	√	√	√	√	√	√
3D FEM (F1)		√		√							√
Diff. data (F2)			√
Lung (F3)				√
Elec. move. (F4)					√
Noise weight (I1)						√
Robust errors (I2)							√				√
HPF prior (I3)								√
TSVD (I4)									√
Total variation (I5)										√
Sheffield backproj												√