| No increase of the blood oxygenation level-dependent functional magnetic resonance imaging signal with higher field strength: implications for brain activation studies. | |
| | |
MedLine Citation:
|
PMID: 20392946 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Experimental data up to 7.0 T show that the blood oxygenation level-dependent (BOLD) signal of functional magnetic resonance imaging (fMRI) increases with higher magnetic field strength. Although several studies at 11.7 T report higher BOLD signal compared with studies at 7.0 T, no direct comparison at these two field strengths has been performed under the exact same conditions. It therefore remains unclear whether the expected increase of BOLD effect with field strength will still continue to hold for fields >7.0 T. To examine this issue, we compared the BOLD activation signal at 7.0 and 11.7 T with the two common sequences, spin-echo (SE) and gradient-echo (GE) echo planar imaging (EPI). We chose the physiologically well controlled rat model of electrical forepaw stimulation under medetomidine sedation. While a linear to superlinear increase in activation with field strengths up to 7.0 T was reported in the literature, we observed no significant activation difference between 7.0 and 11.7 T with either SE or GE. Discussing the results in light of the four-component model of the BOLD signal, we showed that at high field only two extravascular contributions remain relevant, while both intravascular components vanish. Constancy of the BOLD effect is discussed due to motional narrowing, i.e., susceptibility gradients become so strong that phase variance of diffusing spins decreases and therefore the BOLD signal also decreases. This finding will be of high significance for the planning of future human and animal fMRI studies at high fields and their quantitative analysis. |
| | |
Authors:
|
J?rg U Seehafer; Daniel Kalthoff; Tracy D Farr; Dirk Wiedermann; Mathias Hoehn |
Related Documents
:
|
16608486 - Orientation of culex mosquitoes to carbon dioxide-baited traps: flight manoeuvres and t... 19096456 - Sinusoidal magnetic field stimulates magnetosome formation and affects mama, mms13, mms... 21483016 - Advances in imaging and the management of myeloma bone disease. 17854176 - Magnetic properties of bulk bicro3 studied with dc and ac magnetization and specific heat. 22251666 - Predictive value of positron emission tomography - computed tomography image fusion in ... 22226376 - Role of imaging techniques in the tnm classification of non-small cell bronchogenic car... |
Publication Detail:
|
Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The Journal of neuroscience : the official journal of the Society for Neuroscience Volume: 30 ISSN: 1529-2401 ISO Abbreviation: J. Neurosci. Publication Date: 2010 Apr |
Date Detail:
|
Created Date: 2010-04-15 Completed Date: 2010-05-14 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8102140 Medline TA: J Neurosci Country: United States |
Other Details:
|
Languages: eng Pagination: 5234-41 Citation Subset: IM |
Affiliation:
|
In-Vivo NMR Laboratory, Max Planck Institute for Neurological Research, D-50931 Cologne, Germany. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Animals Brain / blood supply, physiology* Electric Stimulation Forelimb / physiology Magnetic Resonance Imaging / instrumentation*, methods* Male Models, Animal Oxygen / blood* Rats Rats, Wistar Time Factors Touch Perception / physiology |
| Chemical | |
Reg. No./Substance:
|
7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: During visual word recognition, phonology is accessed within 100 ms and may be mediated by a speech ...
Next Document: Essential role of the redox-sensitive kinase p66shc in determining energetic and oxidative status an...