Appearance modeling of11C PiB PET images: Characterizing amyloid deposition in Alzheimer's disease, mild cognitive impairment and healthy aging

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2008-11, Vol.43 (3), p.430
• Main Authors: Fripp, Jurgen, Bourgeat, Pierrick, Acosta, Oscar, Raniga, Parnesh, Modat, Marc, Pike, Kerryn E, Jones, Gareth, O'Keefe, Graeme, Masters, Colin L, Ames, David, Ellis, Kathryn A, Maruff, Paul, Currie, Jon, Villemagne, Victor L, Rowe, Christopher C, Salvado, Olivier, Ourselin, Sébastien
• Format: Article
• Language: English
• Subjects: Alzheimer's disease; Cognitive ability; Principal components analysis
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2008.07.053

β-amyloid (Aβ) deposition is one of the neuropathological hallmarks of Alzheimer's disease (AD), Aβ burden can be quantified using11C 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 in11C 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 Aβ 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 werePiB+formed a distinct cluster that was between, but separated from the AD andPiB-NC clusters. ThePiB+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.