Convolution reconstruction of fan beam projections

✍ Scribed by Philip Dreike; Douglas P. Boyd

• Publisher: Elsevier Science
• Year: 1976
• Weight: 749 KB
• Volume: 5
• Category: Article
• ISSN: 0146-664X
• DOI: 10.1016/s0146-664x(76)80032-9

✦ Synopsis

An algorithm is presented for reordering and interpolating a set of fan beam projections into an equivalent set of equispaced parallel ray projections, which may then be reconstructed by the convolution method of Bracewell and Riddle ,~s implemented by Ramachandran and Lakshminarayanan. This algorithm, is of interest because it opens the possibility of combining high speed parallel data collection with a coraputatieaaily inexpensive reconstruction algorithm. The requlmd sets of parallel rays are obtained by appropriately selecting single rays fi'om each of several fan beams. A satisfactory balance between the munber of rays per parallel ray projection and the number of projections is obtained by the introduction of a "slant" approximation. The restriction of the convoh~tion method to equally spaced rays is then satisfied by a rebinning of the reordered data. Experimental reconstructions of a head projection and simulated data are presented.