RecruitingPhase 1Radiation therapyPET Imaging of Vaso-Occlusive Crisis (VOC) in SCDThe purpose of this study is to find objective biomarkers of vaso-occlusion (blood vessel blockage) in people with SCD. Using information from earlier studies and work being done, researchers have developed a strategy to image VOC, using positron emission tomography (PET). The ability to see and measure VOC in SCD patients can help patient care, by showing when and how a VOC is occurring or going to occur. Studying this method will also help in future drug research, as it will allow researchers to deliver promising new medications that target hyper-adhesion and sickling in people with SCD.