Fig. 1

Front, side, top, and oblique views of SORs for coincidences detected in opposite detector elements on a detector surface (gray) for three different energies of the scattered photon: 460 keV (innermost, darkest), 358 keV (middle), and 307 keV (outermost, lightest). Assuming the scattered photon in the left detector, one potential broken LOR is indicated, with the solid part indicating potential activity source locations. Each broken LOR runs inside its SOR, touching it only at the detectors and one potential scattering location. Adapted, with permission, from ([17], Figure 2). Ⓒ 2014 American Association of Physicists in Medicine