Document Detail

"Voxel-based morphometry" should not be used with imperfectly registered images.
MedLine Citation:
PMID:  11707101     Owner:  NLM     Status:  MEDLINE    
John Ashburner and Karl Friston (2000) introduced a standardized method of "voxel-based morphometry" (VBM) for comparisons of local concentrations of gray matter between two groups of subjects. Segmented images of gray matter from grossly normalized high-resolution images are smoothed and their group differences analyzed by the now-conventional voxelwise Worsley approach to Gaussian random fields of differences. This comment concerns an unfortunate interaction between the algorithm's spatial normalization and voxelwise comparison steps, whereby several obvious quantitative confounds are injected at the core of the inference engine the authors put forward. Specifically, the statistics of the resulting voxelwise comparisons are uninformative about group differences wherever the spatial normalization algorithm has failed to register on any robustly appearing image gradient. The method of Ashburner and Friston is defensible only far from all image gradients.
F L Bookstein
Publication Detail:
Type:  Comment; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  NeuroImage     Volume:  14     ISSN:  1053-8119     ISO Abbreviation:  Neuroimage     Publication Date:  2001 Dec 
Date Detail:
Created Date:  2001-11-14     Completed Date:  2002-01-15     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9215515     Medline TA:  Neuroimage     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1454-62     Citation Subset:  IM    
Copyright Information:
Copyright 2001 Academic Press.
University of Michigan, USA.
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MeSH Terms
Brain / anatomy & histology*
Image Enhancement*
Image Processing, Computer-Assisted*
Magnetic Resonance Imaging*
Mathematical Computing
Normal Distribution
Grant Support
Comment On:
Neuroimage. 1997 Nov;6(4):344-52   [PMID:  9417976 ]
Comment In:
Neuroimage. 2001 Dec;14(6):1238-43   [PMID:  11707080 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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