Removal of phase artifacts from fMRI data using a Stockwell transform filter improves brain activity detection

dc.contributor.authorGoodyear, Bradley G.
dc.contributor.authorZhu, Hongmei
dc.contributor.authorBrown, Robert A.
dc.contributor.authorMitchell, Joseph
dc.date.accessioned2007-03-29T23:32:20Z
dc.date.available2007-03-29T23:32:20Z
dc.date.issued2004
dc.description.abstractA novel and automated technique is described for removing fMRI image artifacts resulting from motion outside of the imaging field of view. The technique is based on the Stockwell transform (ST), a mathematical operation that provides the frequency content at each time point within a time-varying signal. Using this technique, 1D Fourier transforms (FTs) are performed on raw image data to obtain phase profiles. The time series of phase magnitude for each and every point in the phase profile is then subjected to the ST to obtain a time-frequency spectrum. The temporal location of an artifact is identified based on the magnitude of a frequency component relative to the median magnitude of that frequency’s occurrence over all time points. After each artifact frequency is removed by replacing its magnitude with the median magnitude, an inverse ST is applied to regain the MR signal. Brain activity detection within fMRI datasets is improved by ignificantly reducing image artifacts that overlap anatomical regions of interest. The major advantage of ST-filtering is that artifact frequencies may be removed within a arrow time-window, while preserving the frequency information at all other time points.
dc.identifier.citationGoodyear, B. G., Zhu, H. , Brown, R. A. and Mitchell, J. R. (2004), "Removal of phase artifacts from fMRI data using a Stockwell transform filter improves brain activity detection." Magn. Reson. Med., 51: 16-21. doi:10.1002/mrm.10681
dc.identifier.issn0740-3194
dc.identifier.urihttp://hdl.handle.net/10315/928
dc.identifier.urihttps://doi.org/10.1002/mrm.10681
dc.language.isoen
dc.publisherMagnetic Resonance in Medicine
dc.subjectfMRI
dc.subjectartifacts
dc.subjectfiltering
dc.subjectStockwell transform
dc.subjectFourier transform
dc.subjectmotion
dc.titleRemoval of phase artifacts from fMRI data using a Stockwell transform filter improves brain activity detection
dc.typeArticle

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