title: Scaled subprofile model: a statistical approach to the analysis of functional patterns in positron emission tomographic data.
abstract: The data obtained from measurements of regional rCMRglu using [18F]fluorodeoxyglucose (FDG)/positron emission tomographic (PET) data contain more structure than can be identified with group mean rCMRglu profiles or regional correlation coefficients. This additional structure is revealed by a novel mathematical-statistical model of regional metabolic interactions that explicitly represents rCMRglu profiles as a combination of region-independent global effects, a group mean pattern and a mosaic of interacting networks. In its application to FDG/PET data, this model removes global subject effects [global scaling factors (GSFs)] and a group mean pattern (profile) so as to maximize statistical power for the detection and simultaneous discovery of all networks of two or more regions that form a significant and consistent linearly covarying pattern. The model approach presented here was applied to the combined rCMRglu data from 12 demented AIDS patients and 18 normal controls: Two significant metabolic covariance pattern descriptors that together accounted for 71 to 96% of the rCMRglu/GSF variation across subjects for 22/28 regions in the AIDS group were extracted. Each descriptor was found to be highly correlated with performance on several neuropsychological tests, providing independent validation of the analysis technique as a means of discovering and describing behaviorally related components of group rCMRglu profiles.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000378:metabolism; D000328:Adult; D001921:Brain / Q000378:metabolism; D003847:Deoxyglucose / Q000031:analogs & derivatives; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008959:Models, Neurological; D013223:Statistics as Topic; D014055:Tomography, Emission-Computed
chemical_list: D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose; D005947:Glucose