1. An electronic storage medium storing a scintillation crystal identification look-up table (LUT) for PET imaging, said LUT comprising: a LUT location corresponding to a center region over a centroid of a scintillation crystal of a PET detector; and LUT locations corresponding to a plurality of radial regions surrounding said center region, wherein the LUT location is identified with radial distance and angular information from the centroid of the scintillation crystal, and wherein the radial distance is converted to a statistical confidence interval.