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P4‐171: In vivo imaging of amyloid plaques by MRI after intravenous administration of a contrast agent
Author(s) -
Santin Mathieu,
Debeir Thomas,
Rooney Thomas,
Dhenain Marc
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.1875
Subject(s) - microbubbles , in vivo , magnetic resonance imaging , ultrasound , gadolinium , medicine , contrast (vision) , amyloid (mycology) , staining , mri contrast agent , pathology , genetically modified mouse , chemistry , transgene , radiology , biochemistry , biology , microbiology and biotechnology , computer science , organic chemistry , artificial intelligence , gene
Background: The present study compared four different structural magnetic resonance imaging (MRI) techniques used to measure gray matter atrophy in Alzheimer’s disease (AD): manual and automated volumetry, cortical thickness (CT) and voxel-based morphometry (VBM)). These techniques are used interchangeably in AD research and thus far it is unclear which technique is superior in detecting abnormalities early in the disease process. We inquired whether these techniques show similar results in healthy controls (con), patients with amnestic mild cognitive impairment (MCI) and patients suffering from mild AD. In addition, we investigated whether atrophy of prefrontal cortex (PFC) or medial temporal lobe (MTL) regions is most indicative of (preclinical) AD. Methods: Three groups of older male participants were selected: 18 healthy participants without anymemory impairment, 18 patients with amnesticMCI, and 18 patients with mild AD. Between-group differences were investigated in PFC and MTL regions. A manual and automatic tracing approach were applied to calculate gray matter volume. CTwas furthermore calculated by Freesurfer as the average thickness of the cortical surface in each ROI. VBM was applied by using masks of atlas-based ROI’s in FSL. Results: Manually measured right parahippocampal gyrus (PHG) volumes can differentiate con and MCI. Con and AD can furthermore be distinguished by manually measured hippocampus and PHGvolumes, and by automatedmeasurements of hippocampus and entorhinal cortex (ERC). Manual segmentation techniques are also sensitive for changes in PFC areas showing abnormalities in inferior and orbital PFC (con /AD andMCI/AD). CTanalysis showed differences between con and AD in ERC, right inferior prefrontal (IPFC) and left medial orbitofrontal cortex (OFC) regions. VBM-ROI analyses showed differences between con/AD andMCI/AD in hippocampus, IPFC andOPFC (Table 1). Conclusions: The present study demonstrates that manual volumetry and VBM are able to detect group differences in both PFC and MTL structures (con/AD and MCI/AD). Manual volumetry of the right PhG can furthermore differentiate between con andMCI. The present study confirms earlier theories that theMTL is most indicative of (preclinical) AD, showing abnormalities in all the investigated techniques.