The lag of cerebral hemodynamics with rapidly alternating periodic stimulation: modeling for functional MRI.
Publication/Presentation Date
1-1-1999
Abstract
A mathematical model that characterizes the response of venous oxygenation to changes in cerebral blood flow (rCBF) and oxygen consumption has been previously presented. We use this model to examine the dampening phenomenon in functional MRI (fMRI) signals with rapidly alternating periodic stimulation bursts. Using a mass balance approach, the equations for an input-output model are derived and solved using Matlab (the Math Works Inc.). Changes in venous oxygenation are related to the results of fMRI experiments using progressively shorter periods of stimulation. An impulse-response function for the model is derived in an attempt to explore the source of the lag in cerebral hemodynamics. Increasing the frequency of stimulation bursts eventually produces a dampening in the fMRI signal. The dampening phenomenon in fMRI signals occurs with stimulation of high frequency on-off alternation. The dynamics of signal dampening, as well as the impulse-response function of a blood oxygen level-dependent model, lend strong indirect support to the hypothesis that blood oxygen level-dependent contrast at the level of the venous blood pool, rather than R1 inflow effects or changes in oxygenation at the level of the capillary bed, underlies the observed signal changes in fMRI.
Volume
17
Issue
1
First Page
9
Last Page
20
ISSN
0730-725X
Published In/Presented At
Hathout, G. M., Gopi, R. K., Bandettini, P., & Gambhir, S. S. (1999). The lag of cerebral hemodynamics with rapidly alternating periodic stimulation: modeling for functional MRI. Magnetic resonance imaging, 17(1), 9–20. https://doi.org/10.1016/s0730-725x(98)00150-7
Disciplines
Diagnosis | Medicine and Health Sciences | Other Analytical, Diagnostic and Therapeutic Techniques and Equipment | Radiology
PubMedID
9888394
Department(s)
Department of Radiology and Diagnostic Medical Imaging
Document Type
Article