A gaussian mixture model approach for estimating and comparing the shapes of distributions of neuroimaging data: diffusion-measured aging effects in brain white matter.
Neuroimaging signal intensity measures underlying physiology at each voxel unit. The brain-wide distribution of signal intensities may be used to assess gross brain abnormality. To compare distributions of brain image data between groups, t-tests are widely applied. This approach, however, only compares group means and fails to consider the shapes of the distributions. We propose a simple approach for estimating both subject- and group-level density functions based on the framework of Gaussian mixture modeling, with mixture probabilities that are testable between groups. We demonstrate this approach by application to the analysis of fractional anisotropy image data for assessment of aging effects in white matter.
Department of Radiology, The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine , Bronx, NY , USA.
Namhee
N
Kim
Department of Epidemiology and Population Health, Albert Einstein College of Medicine , Bronx, NY , USA.
Moonseong
M
Heo
Department of Radiology, The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine , Bronx, NY , USA.
Roman
R
Fleysher
Department of Radiology, The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine , Bronx, NY , USA ; Department of Physiology and Biophysics, Albert Einstein College of Medicine , Bronx, NY , USA.
Craig A
CA
Branch
Department of Radiology, The Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine , Bronx, NY , USA ; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine , Bronx, NY , USA ; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine , Bronx, NY , USA ; Department of Radiology, Montefiore Medical Center , Bronx, NY , USA.
Michael L
ML
Lipton
Gaussian mixture model; aging effects; density function estimation; diffusion tensor imaging; fractional anisotropy