Derivation of the Extended Fan-Beam Formula
The fan-beam tomographic reconstruction formulas that have previously appeared in the literature have been restricted to the case where the source points are situated on a circle. This paper extends the fan-beam formula to "curves of source points" other than a circle of source points (e.g., a straight line or a hexagon). In the derivation new mathematical techniques are presented. For both the straight line and the hexagon a discrete version of the "extended" formula is developed.