title: Appearance modeling of 11C PiB PET images: characterizing amyloid deposition in Alzheimer's disease, mild cognitive impairment and healthy aging.
abstract: Beta-amyloid (Abeta) deposition is one of the neuropathological hallmarks of Alzheimer's disease (AD), Abeta burden can be quantified using (11)C PiB PET. Neuropathological studies have shown that the initial plaques are located in the temporal and orbitofrontal cortices, extending later to the cingulate, frontal and parietal cortices (Braak and Braak, 1997). Previous studies have shown an overlap in (11)C PiB PET retention between AD, mild cognitive impairment (MCI) patients and normal elderly control (NC) participants. It has also been shown that there is a relationship between Abeta deposition and memory impairment in MCI patients. In this paper we explored the variability seen in 15 AD, 15 MCI and 18 NC by modeling the voxel data from spatially and uptake normalized PiB images using principal component analysis. The first two principal components accounted for 80% of the variability seen in the data, providing a clear separation between AD and NC, and allowing subsequent classification. The MCI cases were distributed along an apparent axis between the AD and NC group, closely aligned with the first principal component axis. The NC cases that were PiB(+) formed a distinct cluster that was between, but separated from the AD and PiB(-) NC clusters. The PiB(+) MCI were found to cluster with the AD cases, and exhibited a similar deposition pattern. The primary principal component score was found to correlate with episodic memory scores and mini mental status examination and it was observed that by varying the first principal component, a change in amyloid deposition could be derived that is similar to the expected progression of amyloid deposition observed from post mortem studies.
authors.affiliation: Australian e-Health Research Center, CSIRO ICT Centre, Brisbane, Australia. jurgen.fripp@csiro.au
authors.forename: Jurgen
authors.initials: J
authors.lastname: Fripp
authors.forename: Pierrick
authors.initials: P
authors.lastname: Bourgeat
authors.forename: Oscar
authors.initials: O
authors.lastname: Acosta
authors.forename: Parnesh
authors.initials: P
authors.lastname: Raniga
authors.forename: Marc
authors.initials: M
authors.lastname: Modat
authors.forename: Kerryn E
authors.initials: KE
authors.lastname: Pike
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
authors.forename: Graeme
authors.initials: G
authors.lastname: O'Keefe
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: David
authors.initials: D
authors.lastname: Ames
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ellis
authors.forename: Paul
authors.initials: P
authors.lastname: Maruff
authors.forename: Jon
authors.initials: J
authors.lastname: Currie
authors.forename: Victor L
authors.initials: VL
authors.lastname: Villemagne
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
authors.forename: Olivier
authors.initials: O
authors.lastname: Salvado
authors.forename: Sébastien
authors.initials: S
authors.lastname: Ourselin
mesh_terms: D000368:Aged; D000375:Aging; D000544:Alzheimer Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D000682:Amyloid; D000814:Aniline Compounds; D052160:Benzothiazoles; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D002250:Carbon Radioisotopes; D003072:Cognition Disorders / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008959:Models, Neurological; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D025341:Principal Component Analysis; D019275:Radiopharmaceuticals; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D052160:Benzothiazoles; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D013844:Thiazoles