A method of reconstructing a three-dimensional image from a set of X-ray projections generated by a scanning system, where the image corresponds to a first volume segment that is a portion of a longer object, includes reconstructing a first estimate image of a second volume segment larger than the first volume segment. The second volume segment includes the first volume segment. The method also includes applying a weighting function to the first estimate image for masking the first volume segment, so as to produce a hypothetical object image. The method further includes re-projecting the hypothetical object image so as to produce a set of simulated hybrid projections corresponding to the first volume segment. The method also includes reconstructing the hybrid projections so as to produce a three-dimensional image corresponding to the first volume segment.
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