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The early response in fMRI: A modeling approach
Author(s) -
Hathout Gasser M.,
Varjavand Bahram,
Gopi Ramesh K.
Publication year - 1999
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/(sici)1522-2594(199903)41:3<550::aid-mrm18>3.0.co;2-q
Subject(s) - oxidative metabolism , phenomenon , cerebral blood flow , neuroscience , voxel , blood volume , transient (computer programming) , functional magnetic resonance imaging , blood flow , psychology , medicine , physics , metabolism , computer science , radiology , quantum mechanics , operating system
A mathematical model is presented to study the generation of the early response phenomenon in fMRI. Initially, we demonstrate that a simple combination of the changes taking place in cerebral blood volume and flow could create the transient early signal decrease, by analyzing their effects on total per voxel deoxyhemoglobin content. Also, we examine the traditional paradigm for the early response: that it may be caused by an early burst of oxidative metabolism and conclude that such changes also explain the early transient response. We suggest that the volume effect may play a role in the generation of the early response phenomenon along with an early upregulation of oxidative metabolism, and that this role may be important if the early response phenomenon is shown to occur at the level of the venous blood pool, and not just at the level of the capillary bed. Magn Reson Med 1999:41:550–554, 1999. © 1999 Wiley‐Liss, Inc.