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 used 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.~Findings from this study will demonstrate the distribution of opioid effects in brain and other organs in healthy controls and individuals with opioid use disorder (OUD), including those treated with the opioid agonists buprenorphine or methadone. Thus, this project will inform clinically relevant questions related to OUD.~PET/CT imaging will be used to evaluate the distribution of opioid effects in the brain and other organs using the investigational radiotracer [11C]carfentanil. Each subject will have an initial [11C]carfentanil positron emission tomography/computed tomography (PET/CT) scan. Subjects not receiving MAT for OUD may undergo a second scan that includes pretreatment with parenteral naloxone.~Analyses will compare the binding potential (BPND) in the brain and other body parts across the three cohorts (OUD+/MAT+, OUD+/MAT-, HC). In the two groups not receiving MAT (OUD+/MAT- and HC), binding potential and distribution will be compared between subjects by contrasting the [11C]carfentanil-only scan with the [11C]carfentanil scan preceded by naloxone treatment. A structural MRI scan of the brain and spinal cord will be conducted before the PET scan to permit co-registration and the identification of specific brain regions on PET scan.~During each PET scan, participants will undergo approximately 90 minutes of dynamic scanning of the brain and body in a whole-body PET/CT scanner. PET/CT imaging sessions will include an injection of ≤ 15 mCi (approximate range for most studies is anticipated to be 5-15 mCi) of [11C]carfentanil. In the non-MAT groups, a dose of naloxone will be injected intravenously approximately 10-15 minutes beforethe [11C]carfentanil injection. Data will be collected to evaluate the uptake of [11C]carfentanil in the brain and other organs with and without naloxone blockade. Venous blood samples will be taken during the scan session to measure radioactive counts and/or bio-metabolites.~Subjects are required to have had a brain MRI performed within 1 year prior to study enrollment, or if the subject has not had a brain MRI deemed acceptable for use for this study, they will be asked to undergo a research brain MRI after they have consented for this study.
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.