1. A method of reconstructing an image from a positron emission tomography scan, comprising: detecting a plurality of photons selected from scattered photons and unscattered photons by a plurality of detectors; identifying a time interval for each of the plurality of photons by a processing device; matching each of the plurality of photons into a plurality of pairs of coincident photons based upon a substantially simultaneous time interval identified by the processing device; measuring an energy produced by each of the plurality of photons by the plurality of detectors; based on the energy produced, determining a scattering angle for each pair of coincident photons from an annihilation point relative to the position of the plurality of detectors by the processing device; and reconstructing an image using a reconstruction algorithm, wherein the reconstruction algorithm uses the scattering angle of each pair of coincident photons.