Breast PET scanners can be used for early diagnosis of breast cancer and decline the number of women who “call back for extra evaluations/tests in response to breast cancer. Our designed scanner is equipped with two planar detectors the size of 4 × 12 × 15 cm and 180 crystal segments with dimensions of 4 × 4 × 0.5 cm their separation distance can mechanically adjust between 4 cm to 8 cm. Two types of detector materials include Lutetium Oxyorthoscilicate LSO(Ce) scintillator and Cadmium Zinc Telluride (CZT) were used separately to evaluate their performance. For scanning first, the patient lay in a prone state on a dedicated bed with two adjustable holes on it where both patient's breasts were located in the holes. As the scanner is dual head, doing transformation between the breasts is easy and can perform through a robotic arm that moves the PET detector's heads from the first to the second breast. Two different scanning approaches were performed in this study, first, the gantry was kept fixed and a partial scan was achieved (Static-scan) and second the detectors start to rotate 90 degrees around the patient’s breast to collect fully tomographic datasets (Dynamic-scan).To assess our designed scanner the spatial resolution, sensitivity, and noise equivalent count ratio (NECR) are estimated based on the NEMA NU-4-2008 standard.