In:
Journal of Cerebral Blood Flow & Metabolism, SAGE Publications, Vol. 40, No. 9 ( 2020-09), p. 1859-1868
Abstract:
In vivo dopamine D2-receptor availability is frequently assessed with 11 C-raclopride and positron emission tomography. Due to low signal-to-noise ratios for 11 C-raclopride in areas with low D2 receptor densities, the ligand has been considered unreliable for measurements outside the dopamine-dense striatum. Intriguingly, recent studies show that extrastriatal 11 C-raclopride binding potential (BP ND ) values are (i) reliably higher than in the cerebellum (where D2-receptor levels are negligible), (ii) correlate with behavior in the expected direction, and (iii) showed good test–retest reliability in a sample of younger adults. The present work demonstrates high seven-month test–retest reliability of striatal and extrastriatal 11 C-raclopride BP ND values in healthy, older adults (n = 27, age: 64–78 years). Mean 11 C-raclopride BP ND values were stable between test sessions in subcortical nuclei, and in frontal and temporal cortices (p 〉 0.05). Across all structures analyzed, intraclass correlation coefficients were high (0.85–0.96), absolute variability was low (mean: 4–8%), and coefficients of variance ranged between 9 and 25%. Furthermore, regional 11 C-raclopride BP ND values correlated with previously determined 18 F-fallypride BP ND values (ρ = 0.97 and 0.92 in correlations with and without striatal values, respectively, p 〈 0.01) and postmortem determined D2-receptor densities (including striatum: ρ = 0.92; p 〈 0.001; excluding striatum: ρ = 0.75; p = 0.067). These observations suggest that extrastriatal 11 C-raclopride measurements represent a true D2 signal.
Type of Medium:
Online Resource
ISSN:
0271-678X
,
1559-7016
DOI:
10.1177/0271678X19874770
Language:
English
Publisher:
SAGE Publications
Publication Date:
2020
detail.hit.zdb_id:
2039456-1
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