Methods and systems are provided for correcting positional errors in an image arising from gaps in a detector assembly. In one embodiment, a method comprises generating a sinogram based on a plurality of photon coincidence events, selectively inserting one or more pseudo-slices into the sinogram, and generating an image based on the sinogram including the one or more pseudo-slices. In this way, positional errors may be reduced without modifying an image reconstruction algorithm to include a full detector geometry or modifying the detector geometry itself.