Premium
The Fornix Sign: A Potential Sign for Alzheimer's Disease Based on Diffusion Tensor Imaging
Author(s) -
Oishi Kenichi,
Mielke Michelle M.,
Albert Marilyn,
Lyketsos Constantine G.,
Mori Susumu
Publication year - 2012
Publication title -
journal of neuroimaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.822
H-Index - 64
eISSN - 1552-6569
pISSN - 1051-2284
DOI - 10.1111/j.1552-6569.2011.00633.x
Subject(s) - fornix , medicine , sign (mathematics) , diffusion mri , fractional anisotropy , magnetic resonance imaging , radiology , hippocampus , mathematical analysis , mathematics
BACKGROUND We investigated a simple imaging sign for Alzheimer's disease (AD), using diffusion tensor imaging (DTI). We hypothesized that a reduction in fractional anisotropy (FA) in the fornix could be utilized as an imaging sign.METHODS Twenty‐three patients with AD, 24 patients with amnestic mild cognitive impairment (aMCI), and 25 control participants (NC) underwent DTI at baseline and 1 year later. The diagnosis was reevaluated 1 year and 3 years after the initial scan. A color‐scaled FA map was used to visually identify the FA reduction (“fornix sign”). We investigated whether the fornix sign could separate AD from NC, and could predict progression from aMCI to AD or NC to aMCI. We also quantified FA of the fornix to validate the fornix sign.RESULTS The fornix sign was identical to the lack of any voxels with an FA > .52 within the fornix. The fornix sign differentiated AD from NC with specificity of 1.0 and sensitivity of .56. It predicted conversion from NC to aMCI with specificity of 1.0 and sensitivity of .67, and from aMCI to AD with specificity of .94 and sensitivity of .83.CONCLUSION The fornix sign is a promising predictive imaging sign of AD.