Abstract
BACKGROUND AND PURPOSE: Early stratification of degenerative processes is a prerequisite to warrant therapeutic options in prodromal Alzheimer disease. Our aim was to investigate differences in cerebral macromolecular tissue composition between patients with AD, mild cognitive impairment, and age- and sex-matched healthy controls by using model-based magnetization transfer with a binary spin-bath magnetization transfer model and magnetization transfer ratio at 1.5T.
MATERIALS AND METHODS: We investigated patients with de novo AD (n = 18), MCI (n = 18), and CTRLs (n = 18). A region-of-interest analysis of the entorhinal cortex, hippocampal head and body, insula, and temporal neocortex was performed with fuzzy clustering to associate every subregion to a cluster representative for each group.
RESULTS: Cluster analysis achieved a concordance of 0.92 (50 of 54 subjects) between a combination of the calculated mMT parameters (kf,kr,T2r,F,T2f) in the entorhinal cortex and the neuropsychological diagnosis. The sensitivity and specificity for the discrimination of AD from MCI reached 1 and 0.94, with a positive predictive value of 0.95 and a negative predictive value of 1. Compared with mMT, the concordance for MTR was 0.83 (45 of 54 subjects) with a lower specificity of 0.5 and positive predictive value of 0.67 to discriminate patients with AD and MCI.
CONCLUSIONS: mMT imaging detects macromolecule-related alterations and allows an improved classification of patients with early AD and MCI compared with MTR.
ABBREVIATIONS:
- AD
- Alzheimer disease
- CERAD-NAB
- German Version of the Consortium to Establish a Registry on Alzheimer's Disease–Neuropsychological Assessment Battery
- CI
- confidence interval
- CTRLs
- healthy controls
- MCI
- mild cognitive impairment
- mMT
- model-based magnetization transfer
- MTR
- magnetization transfer ratio
- © 2013 by American Journal of Neuroradiology