Simultaneous PET-MRI studies of the concordance of atrophy and hypometabolism in syndromic variants of Alzheimer's disease and frontotemporal dementia: An extended case series

Kuven K. Moodley, Daniela Perani, Ludovico Minati, Pasquale Anthony Della Rosa, Frank Pennycook, John C. Dickson, Anna Barnes, Valeria Elisa Contarino, Sofia Michopoulou, Ludovico D'Incerti, Catriona Good, Federico Fallanca, Emilia Giovanna Vanoli, Peter J. Ell, Dennis Chan

Research output: Contribution to journalArticle

Abstract

Background: Simultaneous PET-MRI is used to compare patterns of cerebral hypometabolism and atrophy in six different dementia syndromes. Objectives: The primary objective was to conduct an initial exploratory study regarding the concordance of atrophy and hypometabolism in syndromic variants of Alzheimer's disease (AD) and frontotemporal dementia (FTD). The secondary objective was to determine the effect of image analysis methods on determination of atrophy and hypometabolism. Method: PET and MRI data were acquired simultaneously on 24 subjects with six variants of AD and FTD (n = 4 per group). Atrophy was rated visually and also quantified with measures of cortical thickness. Hypometabolism was rated visually and also quantified using atlas-and SPM-based approaches. Concordance was measured using weighted Cohen's kappa. Results: Atrophy-hypometabolism concordance differed markedly between patient groups; kappa scores ranged from 0.13 (nonfluent/agrammatic variant of primary progressive aphasia, nfvPPA) to 0.49 (posterior cortical variant of AD, PCA). Heterogeneity was also observed within groups; the confidence intervals of kappa scores ranging from 00.25 for PCA to 0.290.61 for nfvPPA. More widespread MRI and PET changes were identified using quantitative methods than on visual rating. Conclusion: The marked differences in concordance identified in this initial study may reflect differences in the molecular pathologies underlying AD and FTD syndromic variants but also operational differences in the methods used to diagnose these syndromes. The superior ability of quantitative methodologies to detect changes on PET and MRI, if confirmed on larger cohorts, may favor their usage over qualitative visual inspection in future clinical diagnostic practice.

Original languageEnglish
Pages (from-to)639-653
Number of pages15
JournalJournal of Alzheimer's Disease
Volume46
Issue number3
DOIs
Publication statusPublished - Jun 25 2015

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Keywords

  • Alzheimer's disease
  • atrophy
  • frontotemporal dementia
  • hypometabolism
  • NEUROSTAT
  • simultaneous PET-MRI
  • statistical parametric mapping
  • visual rating

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Geriatrics and Gerontology
  • Clinical Psychology

Cite this

Moodley, K. K., Perani, D., Minati, L., Anthony Della Rosa, P., Pennycook, F., Dickson, J. C., Barnes, A., Elisa Contarino, V., Michopoulou, S., D'Incerti, L., Good, C., Fallanca, F., Giovanna Vanoli, E., Ell, P. J., & Chan, D. (2015). Simultaneous PET-MRI studies of the concordance of atrophy and hypometabolism in syndromic variants of Alzheimer's disease and frontotemporal dementia: An extended case series. Journal of Alzheimer's Disease, 46(3), 639-653. https://doi.org/10.3233/JAD-150151