Multi-System Analysis of Opioid Receptor Binding

This study will enroll up to 60 adults (including 30 females and 30 males) in three cohorts of up to 20 subjects each. In all three groups, \[11C\]carfentanil whole-body PET imaging will be used to examine the central nervous system (CNS) and broader systemic opioid binding in an initial scan session. In the two groups not receiving standard of care medication assisted treatment (MAT) for opioid use disorder (OUD) the effects on \[11C\]carfentanil binding potential of the blockade of opioid binding by the non-selective opioid antagonist naloxone administered parenterally in a second scan session will also be examined. If two scans are completed they can be done on the same day or on different days.