Handling of Long Objects in Iterative Reconstruction from Helical Cone-Beam Projections
2005 (English)In: Fully 3D 2005, Eighth International Meeting on Fully Three-dimensional Image Reconstruction in Radiology and Nuclear Medicine,2005, 2005Conference paper (Refereed)
Contemporary analytical reconstruction methods for helical cone-beam CT have to be designed to handle the Long Object Problem. Normally, a moderate amount of over-scanning is sufficient for reconstruction of a certain Region-of-interest (ROI). Unfortunately, for iterative methods, it seems that the useful ROI will diminish for every iteration step. The remedies proposed here are twofold. Firstly, we use careful extrapolation and masking of projection data. Secondly, we generate and utilize projection data from incompletely reconstructed volume parts, which is rather counter-intuitive and contradictory to our initial assumptions. The results seem very encouraging. Even voxels close to the boundary in the original ROI are as well enhanced by the iterative loop as the middle part.
Place, publisher, year, edition, pages
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-42661Local ID: 67760OAI: oai:DiVA.org:liu-42661DiVA: diva2:263518