Table 2.
A summary of the key results with opioid PET in clinical research.
| Condition | Ligand | Main Finding | Ref. |
|---|---|---|---|
| Healthy aging | [11C]Caf (8) (µOR) |
20% decrease in frontal cortex (females) | [137] |
| Epilepsy | [11C]Caf (8) (µOR) |
Increased in ipsilateral temporal lobe, decreased in amygdala | [140] |
| Epilepsy | [11C]DPN (15) (mixed ligand) |
No change | [140] |
| Parkinson’s disease | [11C]DPN (15) (mixed ligand) |
20–30% decrease in striatum and thalamus only in those patients with iatrogenic DOPA-dyskinesia | [147] |
| Huntington’s disease | [11C]DPN (15) (mixed ligand) |
30% reduced in caudate/putamen | [150] |
| Pontine infarct central pain | [11C]DPN (15) (mixed ligand) |
Reduced throughout pain network | [151] |
| Capsaicin-induced acute pain | [11C]Caf (8) (µOR) |
Up to 50% decrease contralateral thalamus, in proportion to subjective severity | [155] |
| Sustained painful stimulus of the jaw muscle with saline injection | [11C]Caf (8) (µOR) |
Blateral decrease in binding in the ipsilateral amygdala (5%) and contralateral ventro-lateral thalamus (7%) | [157] |
| painful heat | [11C]Caf (8) (µOR) |
Placebo effect on binding changes | [170] |
| Acupuncture therapy with sham acupuncture control | [11C]Caf (8) (µOR) |
Persistent 10–30% increases in µ-OR binding in pain-related brain regions | [173] |
| Harm avoidance trait in healthy males | [18F]FE-DPN (16) (mixed ligand) | Trait correlated positively with binding in vental striatum, suggesting link with substance abuse | [181] |
| Correlation with BOLD signal responses A large group of healthy women, binding. to viewing emotionally arousing scenes | [11C]Caf (8) (µOR) |
Negative correlation in amygdala, hippocampus, thalamus, and hypothalamus | [185] |
| Major depressive disorder | [11C]GR103545 (25) (κOR) | No difference from controls | [190] |
| Detoxified cocaine addicts | [11C]Caf (8) (µOR) | Increased in frontal and cingulate cortex, which correlated with the extent of craving | [195] |
| Detoxified alcohol-dependent subjects | [11C]MeNTI (22) (δOR) | Globally 10–20% increased binding inverse relationship in some regions with intensity of craving | [203] |
| Obesity (BMI > 40) | [11C]Caf (8) (µOR) |
Globally 20% lower compared to lean volunteers | [218] |
| Feeding, regardless of the hedonic experience in non-obese subjects | [11C]Caf (8) (µOR) |
Widespread decreases in binding | [222] |