A technique for 3D tomographic image reconstruction in the circular geometry (e.g., cone-based circular geometry) is disclosed. The technique may include data filtering using an initial 2D Laplace operation and a subsequent, non-local 2D filtering operation. The first filtering step thus only acts locally on the data so that it can be carried out accurately even in presence of (transaxial) data truncation. This feature may provide increased flexibility with respect to truncated projections as compared with certain standard FBP methods. Simulation studies show that the technique yields, for heavily transaxially-truncated data, an image quality that is similar to that obtained with the Feldkamp method applied with an explicit extrapolation scheme.
