Additional Study Information: Pain is a natural response to injury to let us know there may be damage to our bodies. Pain is the way our body tells us that we must take care of ourselves. Chronic pain is different and lasts for a long time. In some cases, chronic pain remains without any sign of body damage. Today, there is no way for a doctor to measure someone's chronic pain or accurately determine many details about chronic pain. The investigators at Columbia University are interested in new imaging test that could help doctors look at chronic pain and help patients with chronic pain. The new imaging test uses a new drug called 11C-NOP46. 11C-NOP46 is a radioactive drug and is experimental. It is not approved by the Food and Drug Administration (FDA). The investigators believe that, when given to patients, this new drug can go to the exact places of chronic pain within the body. Once the drug goes to the places of chronic pain, a special camera, called a Positron Emission Tomography (PET) camera, can be used to take pictures of the drug. In this study, the investigators will give 11C-NOP46 to up to 35 subjects. Once you sign up, a study team member may contact you to discuss the study with you and ask some pre-screening questions.