Document Detail


Comparison of BOLD and direct-MR neuronal detection (DND) in the human visual cortex at 3T.
MedLine Citation:
PMID:  18956466     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Direct-MR neuronal detection (DND) of transient magnetic fields has recently been investigated as a novel imaging alternative to the conventional BOLD functional MRI (fMRI) technique. However, there remain controversial issues and debate surrounding this methodology, and this study attempts clarification by comparing BOLD responses in the human visual system with those of DND. BOLD relies on indirectly measuring blood oxygenation and flow changes as a result of neuronal activity, whereas the putative DND method is based on the hypothesis that the components of the in vivo neuronal magnetic fields, which lie parallel to the B(0) field, can potentially modulate the MR signal, thus providing a means of direct detection of nerve impulses. Block paradigms of checkerboard patterns were used for visual stimulation in both DND and BOLD experiments, allowing detection based on different frequency responses. This study shows colocalization of some voxels with slow BOLD responses and putative fast DND responses using General Linear Model (GLM) analysis. Frequency spectra for the activated voxel cluster are also shown for both stimulated and control data. The mean percentage signal change for the DND responses is 0.2%, corresponding to a predicted neuronal field of 0.14 nT.
Authors:
Li Sze Chow; Andrew Dagens; Ying Fu; Greg G Cook; Martyn N J Paley
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Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine     Volume:  60     ISSN:  1522-2594     ISO Abbreviation:  Magn Reson Med     Publication Date:  2008 Nov 
Date Detail:
Created Date:  2008-11-03     Completed Date:  2009-02-12     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8505245     Medline TA:  Magn Reson Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1147-54     Citation Subset:  IM    
Affiliation:
Section of Academic Radiology, University of Sheffield, Sheffield, UK.
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MeSH Terms
Descriptor/Qualifier:
Adult
Algorithms
Brain Mapping / methods*
Evoked Potentials, Visual / physiology*
Female
Humans
Image Enhancement / methods*
Image Interpretation, Computer-Assisted / methods*
Magnetic Resonance Imaging / methods*
Male
Middle Aged
Neurons / cytology,  physiology*
Reproducibility of Results
Sensitivity and Specificity
Visual Cortex / cytology,  physiology*

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


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