Graeme J. O'Keefe

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OBJECTIVE Elucidating the role of aggregated beta-amyloid in relation to gray matter atrophy is crucial to the understanding of the pathological mechanisms of Alzheimer disease and for the development of therapeutic trials. The present study aims to assess this relationship. METHODS Brain magnetic resonance imaging and [(11)C]Pittsburgh compound B(More)
The relationship between β-amyloid deposition and memory deficits in early Alzheimer's disease is unresolved, as past studies show conflicting findings. The present study aims to determine the relative contribution of regional β-amyloid deposition, hippocampal atrophy and white matter integrity to episodic memory deficits in non-demented older individuals(More)
BACKGROUND Supported by compelling genetic data regarding early-onset familial Alzheimer disease (AD), the amyloid beta-peptide (Abeta)-centric theory holds that Abeta is involved in the pathogenesis of sporadic AD. Mutations in the amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) genes lead to increased Abeta levels before(More)
UNLABELLED PET offers a noninvasive means to assess neoplasms, in view of its sensitivity and accuracy in staging tumors and potentially in monitoring treatment response. The aim of this study was to evaluate newly diagnosed primary brain tumors for the presence of hypoxia, as indicated by the uptake of 18F-fluoromisonidazole (18F-FMISO) and to examine the(More)
Respiratory motion artifacts can be a significant factor that limits the PET image quality. To improve image quality, surveillance systems have been developed to track the movements of the subject during scanning. Gating techniques utilizing the tracking information, are able to compensate for subject motion, thereby improving lesion detection. In this(More)
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