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Filtered Backprojection
With FBP, not so much can be optimized, except for the reconstruction kernel,
which can be chosen to control the Modulation Transfer Function (i.e. the
spatial frequency response of the algorithm).
Smooth kernels reduce noise and spatial frequency.
Sharp kernels allow to see more fine structures, but introduce more noise in
the image.
Furthermore:
- all approximation done to solve the inverse problem might generate
artifacts,
- to reconstruct an image, the rotation must be at least 180° plus fan angle.
MTFs