Premium
The intravascular contribution to fmri signal change: monte carlo modeling and diffusion‐weighted studies in vivo
Author(s) -
Boxerman Jerrold L.,
Bandettini Peter A.,
Kwong Kenneth K.,
Baker John R.,
Davis Timothy L.,
Rosen Bruce R.,
Weisskoff Robert M.
Publication year - 1995
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/mrm.1910340103
Subject(s) - signal (programming language) , nuclear magnetic resonance , monte carlo method , susceptibility weighted imaging , functional magnetic resonance imaging , magnetic resonance imaging , neuroscience , physics , computer science , medicine , radiology , mathematics , psychology , statistics , programming language
Understanding the relationship between fMRI signal changes and activated cortex is paramount to successful mapping of neuronal activity. To this end, the relative extravascular and intravascular contribution to fMRI signal change from capillaries (localized), venules (less localized) and macrovessels (remote, draining veins) must be determined. In this work, the authors assessed both the extravascular and intravascular contribution to blood oxygenation level‐dependent gradient echo signal change at 1.5 T by using a Monte Carlo model for susceptibility‐based contrast in conjunction with a physiological model for neuronal activation‐induced changes in oxygenation and vascular volume fraction. The authors compared our Model results with experimental fMRI signal changes with and without velocity sensitization via bipolar gradients to null the intravascular signal. The model and experimental results are in agreement and suggest that the intravascular spins account for the majority of fMRI signal change on T 2 * ‐weighted images at 1.5 T.