Abstract Details

Title Voxelwise Multivariate Analysis of Multimodality Magnetic Resonance Imaging

Topic Aging and Dementia

Presentation(s) P06 - (-)

Poster/Presentation
Number 026

Objective

Background BACKGROUND: Most brain magnetic resonance imaging (MRI) studies concentrate on a single MRI contrast or modality, frequently structural MRI. By performing an integrated analysis of several modalities, such as structural, perfusion-weighted, and diffusion-weighted MRI, new insights may be attained to better understand the underlying processes of brain diseases.

Design/Methods DESIGN/METHODS: We compare two voxelwise approaches: (1) fitting multiple univariate models, one for each outcome and then adjusting for multiple comparisons among the outcomes and (2) fitting a multivariate model. In both cases, adjustment for multiple comparisons is performed over all voxels jointly to account for the search over the brain. The multivariate model is able to account for the multiple comparisons over outcomes without assuming independence because the covariance structure between modalities is estimated. To illustrate the power of each approach, we simulate data with multiple outcomes under four different covariance assumptions and analyze a case control study of Alzheimer's disease, in which data from three MRI modalities are available.

Results RESULTS: Simulations show that the multivariate approach is more powerful when the outcomes are correlated and, even when the outcomes are independent, the multivariate approach is just as powerful or more powerful when at least two outcomes are dependent on predictors in the model. However, multiple univariate regressions with Bonferroni correction remains a desirable alternative in some circumstances.

Conclusions CONCLUSIONS: When choosing a method to account for multiple comparisons, researchers must consider several factors, including the primary hypothesis, whether the correlations between modalities are of interest, and computational resources.

Authors/Disclosures
Melissa Naylor PRESENTER	Ms. Naylor has received personal compensation for serving as an employee of Takeda. Ms. Naylor has stock in Takeda.
	No disclosure on file
Achim Gass, MD (U Hospital Mannheim, U of Heidelberg)	Dr. Gass has nothing to disclose.
	No disclosure on file
Norbert Schuff (VAMC and UCSF)	No disclosure on file
Michael W. Weiner, MD	Dr. Weiner has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Dolby Family Ventures. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Acadia Pharmaceuicals. Dr. Weiner has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Acumen Pharmaceuticals. Dr. Weiner has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Guidepoibnt. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Owkin France. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Quantum Leap Health. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sai MedPartners. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for MEDA Corp.. Dr. Weiner has stock in Anven. Dr. Weiner has stock in Alzeca. Dr. Weiner has stock in Alzheon, Inc.. Dr. Weiner has stock in ALZpath. The institution of Dr. Weiner has received research support from NIH/NIA; National Institutes of Health/National Institutes of Aging. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Speaker/Presenter with Merck Sharp & Dohme. Dr. Weiner has received personal compensation in the range of $0-$499 for serving as a Speaker/Presenter with BrightFocus Foundation. Dr. Weiner has received personal compensation in the range of $500-$4,999 for serving as a Speaker/Presenter with Banner Health.
	No disclosure on file

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