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Artificial shifting of fMRI activation localized by volume- and surface-based analyses

Cited 24 time in Web of Science Cited 24 time in Scopus
Authors
Jo, Hang Joon; Lee, Jong-Min; Kim, Jae-Hun; Choi, Chi-Hoon; Gu, Bon-Mi; Kang, Do-Hyung; Ku, Jeonghun; Kwon, Jun Soo; Kim, Sun I
Issue Date
2008-02-23
Publisher
Elsevier
Citation
Neuroimage. 2008 15;40(3):1077-89.
Keywords
AdultBrain MappingCerebral Cortex/anatomy & histology/physiologyHumansImage Processing, Computer-Assisted/*statistics & numerical dataMagnetic Resonance Imaging/*statistics & numerical dataMaleMotor Cortex/anatomy & histology/physiologyNormal DistributionOxygen/bloodSomatosensory Cortex/anatomy & histology/physiology
Abstract
Spatial smoothing is an important post-processing procedure that is used to increase the signal-to-noise ratio (SNR) of blood oxygenation level-dependent signals (BOLD) in common functional magnetic resonance imaging (fMRI) applications. However, recent studies have shown that smoothing artificially shifts probabilistic local maxima of fMRI activations. In this study, we show shifting of the localization of functional centers in hand motor areas of the cerebral cortex by three-dimensional isotropic Gaussian kernel smoothing or two-dimensional heat kernel smoothing in volume- and surface-based fMRI analyses. Activation maps derived from smoothed echo planar imaging (EPI) data by volume- and surface-based analyses were assigned to the nodes of individual cortical surface models, and local maxima in the primary motor area (M1) and the primary somatosensory cortex (S1) were compared with those derived from non-smoothed risk map analysis, which is commonly used in presurgical applications. For each analysis, the Euclidean and geodesic distances between the correlation coefficients of local maxima derived from smoothed and non-smoothed EPI data were measured. The results show that the correlation coefficients derived from the volume- and surface-based analyses were about 29.4% and 42.9% higher for smoothed than for non-smoothed risk map analyses, and show minimum shifting of localizations by 12.1 mm and 6.9 mm on average in Euclidean distance, respectively, and about 9.5 mm and 5.7 mm on average in geodesic distance, respectively.
ISSN
1053-8119 (Print)
Language
English
URI
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18291680

https://hdl.handle.net/10371/63316
DOI
https://doi.org/10.1016/j.neuroimage.2007.12.036
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College of Medicine/School of Medicine (의과대학/대학원)Psychiatry (정신과학전공)Journal Papers (저널논문_정신과학전공)
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