| 摘要 |
A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of cone beam projection data, each set being acquired on a detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data to form masked data sets. The mask for each data set is formed by cone beam projections onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the data set being masked. The next image reconstruction processing step comprises ramp filtering of each masked data set along a plurality of parallel lines formed therein that are parallel with and in the direction of a parallel projection into the data set of a line that is tangent to the scan path at the source position that acquired that data set and in the direction of the next source position, to generate filtered data sets. Each filtered data set is then subjected to a weighted 3D backprojection into a 3D space, thereby reconstructing in a piecewise manner a 3D image of the ROI in the object.
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