title: 11C-diprenorphine binding in Huntington's disease: a comparison of region of interest analysis with statistical parametric mapping.
abstract: We compare region of interest (ROI) analytical approaches with statistical parametric mapping (SPM) of 11C-diprenorphine positron emission tomography findings in five patients with Huntington's disease (HD) and nine age-matched controls. The ROI were placed on caudate, putamen, and an occipital reference area. Ratios of striatal-occipital uptake from averaged static images centered at 60 minutes showed a mean 20% reduction in caudate (P = 0.034) and 15% reduction in putamen (P = 0.095) receptor binding in the HD patients. Dynamic data from caudate and putamen ROI, together with a plasma tracer input function, were analyzed using spectral analysis to give regional impulse response functions. Regional data at 60 minutes after impulse showed a mean 29% decrease in caudate (P = 0.006) and 23% decrease in putamen (P = 0.029) opioid binding in the HD cohort. Parametric images of tracer binding also were produced with spectral analysis on a voxel basis. The images of the unit impulse response function at 60 minutes showed a mean 31% decrease in caudate (P = 0.005) and a 26% decrease in putamen binding (P = 0.011) in HD. The voxel-based parametric images were transformed into standard stereotactic space, and a between-group comparison (patient versus controls) was performed with SPM. This approach revealed symmetrical decreases in caudate (peak 40% decrease, z score = 4.38) and putamen opioid binding (peak 24% decrease, z score = 4.686) with additional nonhypothesized changes in cingulate, prefrontal, and thalamic areas. The significance and precision of changes measured with spectral analysis applied to dynamic data sets were superior to ROI-based ratio analysis on static images. The SPM replicated the striatal reductions in opioid binding in HD and detected additional nonpredicted changes. This study suggests that SPM is a valid alternative to conventional ROI analytical approaches for determining binding changes with positron emission tomography and may have advantages over region-based analyses in exploratory studies.
authors.affiliation: MRC Cyclotron Unit, Hammersmith Hospital, London, United Kingdom.
authors.forename: R A
authors.initials: RA
authors.lastname: Weeks
authors.forename: V J
authors.initials: VJ
authors.lastname: Cunningham
authors.forename: P
authors.initials: P
authors.lastname: Piccini
authors.forename: S
authors.initials: S
authors.lastname: Waters
authors.forename: A E
authors.initials: AE
authors.lastname: Harding
authors.forename: D J
authors.initials: DJ
authors.lastname: Brooks
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D004174:Diprenorphine / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009292:Narcotic Antagonists / Q000008:administration & dosage*; D011859:Radiography; D011957:Receptors, Opioid / Q000032:analysis / Q000378:metabolism*; D014055:Tomography, Emission-Computed
chemical_list: D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D004174:Diprenorphine