Positron emission tomography (PET) is a nuclear imaging technology (also referred to as molecular imaging) that enables visualization of metabolic processes in the body. The technique detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (also called radiopharmaceuticals, radionuclides or radiotracer). The tracer is injected into a vein on a biologically active molecule, usually a sugar that is used for cellular energy.

Healthcare reform efforts of recent years have challenged the industry to reduce the costs of healthcare for both patients and providers while still maintaining a high quality of care. One of the largest drivers of cost has been repeat hospitalizations, and in 2012, the Centers for Medicare and Medicaid Services (CMS) established the Hospital Readmissions Reduction Program (HRRP) to begin solving the problem.