These Handheld gamma cameras are now an important, well-established technology in the management of cancer, particularly in the detection of sentinel lymph nodes Over the past 5 years, the UI group has devoted a substantial effort in developing a series of compact and high-resolution gamma ray detectors based on small-pixel CdTe/CZT detectors. The previous generation of this detector has been used as the basic building block for a high resolution MR-compatible SPECT system that has produced some preliminary phantom images. The proposed camera modules will be based on the latest iteration of this series of development a gamma ray photon counting CdTe detector with dimension of 1.1cm× 2.2cm × 2cm, which is compact for handheld camera and probe applications. The ERPC CdTe and CDT detectors offer an excellent energy resolution (3–4keV), and a very high spatial resolution (350 um), a DOI resolution of a few hundred microns and all contained in a compact form factor. In this paper, our work will be focused on the evaluation of the ERPC detectors, especially the impact of their excellent energy resolution, spatial resolution and depth of interaction (DOI) resolution for detection and localization of small lesions superimposed on noisy background. These results will be discussed in this paper.