Imaging of the opioid system was one of the earliest applications of Positron Emission Tomography (PET) imaging in neuroscience that remains in widespread use today and in the age of the opioid crisis the technique is as important as ever. In this viewpoint the rich history of opioid imaging using PET is highlighted, including discussion of the preferred radiotracers for imaging of μ, δ, κ and ORL-1 receptors in clinical applications. We also draw attention to key innovations that were essential to development of radiotracers for imaging opioid receptors including production of high molar activity PET radionuclides and new approaches to radiochemistry.
Keywords: molecular imaging; opiate; opioid crisis; positron emission tomography; radiochemistry.