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P1‐086: Alzhiemer's disease: Differentiation from other dementias based on quantitative diffusion tensor imaging on 3 Tesla MRI
Author(s) -
Kumari Rima,
Khushwaha Suman,
Gupta Rohit
Publication year - 2009
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.2009.04.090
Subject(s) - diffusion mri , white matter , fractional anisotropy , corpus callosum , splenium , effective diffusion coefficient , medicine , psychology , nuclear medicine , radiology , pathology , magnetic resonance imaging
extensively studied, the associations between either amyloid biomarker and hippocampal atrophy are not well understood. Methods: 282 ADNI subjects (83 cognitively normal (NC), 140 mild cognitive impairment (MCI) and 59 AD) had baseline cerebrospinal fluid (CSF) Abeta measurements. 98 subjects (19 NC, 62 MCI and 17 AD) underwent PIB PET imaging at follow-up. Using an automated machine-learning algorithm, we segmented the hippocampi in T1-weighted scans from the baseline visit (for Abeta) and the follow-up visit linked to PIB imaging. After 3D radial distance atrophy mapping, we applied linear regression at each hippocampal surface point to reveal associations between the amyloid-based biomarkers (average cortical, parietal and precuneal PIB standardize uptake value ratio (SUVR) and CSF Abeta level) and hippocampal atrophy. We used false discovery rate (FDR) based cumulative distribution plots (CDF) to examine the FDR corrected significance of the association between each amyloid-based biomarker and hippocampal atrophy where functions crossing the y1⁄420x line show significant associations with the variable of interest, accounting for multiple comparisons. Results: CSF Abeta showed significant positive association with hippocampal atrophy (left p1⁄4 0.003; right p1⁄40.0003, top row right panel in Figure 1). Precuneal PIB SUVR showed significant negative association with the right but not left hippocampal radial distance (right p 1⁄40.016, bottom row right panel in Figure 1). Average cortical and parietal PIB SUVR failed to show significant association with hippocampal atrophy. The CDF plot (Figure 1, right panel) identifies only CSF Abeta as significantly associated with hippocampal atrophy. Conclusions: Although both CSF Abeta and PIB measure amyloid, CSF Abeta measures the soluble monomer, while PIB labels fibrillar amyloid. Both CSF Abeta and precuneal PIB SUVR showed significant associations with hippocampal radial distance on the 3D hippocampal maps. However, only CSF Abeta demonstrated an FDR-corrected significant association. Hippocampal atrophy seems to correlate better with with CSF levels of monomer Abeta as opposed to PIB-labeled fibrillar Abeta in neuritic plaques.