Artifact due to B(0) fluctuations in fMRI: correction using the k-space central line.

@article{citeulike:1104617, abstract = {Magnetic resonance experiments require the main magnetic field, B(0), to remain very stable. Several external sources, such as moving ferromagnetic objects and/or changing electromagnetic fields, can significantly change the value of B(0) over time. This work describes an apparent displacement along the phase-encoding axis caused by a variation in B(0). This artifact was observed in fMRI images acquired with EPI. The effect was characterized and tested using an immobile phantom. The image displacement motion along the phase-encoding axis closely followed the changes in B(0). The phase of the central line in the Fourier space was successfully used to correct this artifact. Fluctuations in B(0) may result in artifacts that mimic subject head motion, and must be appropriately corrected. Magn Reson Med 46:198-201, 2001.}, address = {Unit\'{e} de Recherche en R\'{e}sonance Magn\'{e}tique M\'{e}dicale (U2R2M), CHU-Bic\^{e}tre, 78 rue du G\'{e}n\'{e}ral Leclerc, F 94275 Le Kremlin-Bic\^{e}tre Cedex, France. emmanuel.durand@cierm.u-psud.fr}, author = {Durand, E. and van de Moortele, P. F. and Pachot-Clouard, M. and Le Bihan, D.}, citeulike-article-id = {1104617}, issn = {0740-3194}, journal = {Magn Reson Med}, keywords = {artifact, mrs}, month = {July}, number = {1}, pages = {198--201}, posted-at = {2007-02-13 08:17:16}, priority = {2}, title = {Artifact due to B(0) fluctuations in fMRI: correction using the k-space central line.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11443728}, volume = {46}, year = {2001} }

TY - JOUR ID - citeulike:1104617 L3 - citeulike-article-id:1104617 N2 - Magnetic resonance experiments require the main magnetic field, B(0), to remain very stable. Several external sources, such as moving ferromagnetic objects and/or changing electromagnetic fields, can significantly change the value of B(0) over time. This work describes an apparent displacement along the phase-encoding axis caused by a variation in B(0). This artifact was observed in fMRI images acquired with EPI. The effect was characterized and tested using an immobile phantom. The image displacement motion along the phase-encoding axis closely followed the changes in B(0). The phase of the central line in the Fourier space was successfully used to correct this artifact. Fluctuations in B(0) may result in artifacts that mimic subject head motion, and must be appropriately corrected. Magn Reson Med 46:198-201, 2001. IS - 1 JF - Magn Reson Med SN - 0740-3194 AD - Unité de Recherche en Résonance Magnétique Médicale (U2R2M), CHU-Bicêtre, 78 rue du Général Leclerc, F 94275 Le Kremlin-Bicêtre Cedex, France. emmanuel.durand@cierm.u-psud.fr EP - 201 TI - Artifact due to B(0) fluctuations in fMRI: correction using the k-space central line. VL - 46 SP - 198 KW - artifact KW - mrs AU - Durand, E AU - van de Moortele, PF AU - Pachot-Clouard, M AU - Le Bihan, D PY - 2001/07// UR - http://view.ncbi.nlm.nih.gov/pubmed/11443728 ER -