Comments, with reply, on ;Tomographic reconstruction from experimentally obtained cone-beam projections' by S. Webb,...

The above paper (ibid., vol.MI-6, p.67-73, 1987) purports to propose an algorithm and implementation formulas for cone-beam reconstruction. The commenters point out that the exposition of the paper is little more than a paraphrase of their own earlier work (J. Opt. Soc. Amer. A, vol.1, no.6, p.612-19, 1984). All the benefits claimed are intrinsic to the algorithm proposed and were pointed out in the commenters paper. Webb et al. also suggest the use of a modified convolution scheme previously proposed for fan-beam reconstruction. Use of this scheme does not alter the basic premise of the commenters' work and does not entitle Webb et al. to claim to have developed a new algorithm. The authors reply that their paper presents experimental results that are based on the commenters' theoretical results, which were cited in the formers' paper.