Many surgeons advocate for two concurrent imaging studies for the purpose of localizing a parathyroid adenoma. There is level II evidence for utilizing ultrasound as first-line preoperative imaging and Tc-99 m-sestamibi (MIBI) as a confirmatory technique. When there is concordance of the findings of these two imaging modalities, minimally invasive surgery has a cure rate similar to bilateral neck exploration [1, 2]. This chapter addresses the advanced imaging with positron emission tomography/computed tomography (PET/CT) which is not considered first line at this time but may prove useful in select patients.