1. A method of reconstructing an image from a positron emission tomography scan, comprising: detecting a pair of photons by a plurality of detectors, wherein the pair of photons comprises a first photon and a second photon; measuring, by the plurality of detectors, an energy produced by each of the pair of photons; calculating, by a processing device, a first arc and a second arc between detector locations based on the energy produced by each of the pair of photons; determining, by the processing device, a first annihilation area bounded at least in part by the first arc and the second arc, wherein the first annihilation area indicates a plurality of possible locations of an annihilation point from which the pair of photons originated; and reconstructing, by the processing device, an image using a reconstruction algorithm, wherein the reconstruction algorithm uses information regarding the first annihilation area.