[11C]-NOP46

This is an open-label, single center design. In the first stage, five (5) healthy individuals will receive a microdose (10µg) of [11C]-NOP46, immediately followed by whole body positron emission tomography (PET)/computed tomography (CT) to determine dosimetry and perform an initial safety evaluation of the radiotracer. If no toxicities develop, then the investigation will move to the second stage, in which thirty (30) patients with chronic pain will receive a microdose of [11C]-NOP46 followed by PET/CT of region of interests.