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.