Document Detail


Improved cortical-layer specificity of vascular space occupancy fMRI with slab inversion relative to spin-echo BOLD at 9.4 T.
MedLine Citation:
PMID:  18249010     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cerebral blood volume (CBV)-weighted endogenous functional contrast can be obtained by the vascular space occupancy (VASO) technique. VASO relies on nonselective inversion for nulling blood signals, but the implementation of VASO at magnetic fields higher than 3 T is difficult due to converging T(1) values of tissue and blood water and a stronger counteracting blood oxygen level-dependent (BOLD) effect. To improve functional CBV sensitivity, we proposed to use VASO with slab-selective inversion (SI-VASO). Computer simulations showed that the SI-VASO approach significantly increases functional sensitivity compared to the original VASO in a stronger magnetic field with a shorter repetition time. To examine layer-dependent specificity, SI-VASO and spin-echo BOLD (SE-BOLD) functional magnetic resonance imaging (fMRI) experiments were performed on isoflurane-anesthetized cats during visual stimulation at 9.4 T. Unlike simultaneously acquired SE-BOLD signal, the SI-VASO signal peaked at 0.9 mm from the surface of the cortex and was localized to the middle cortical layer. The full-width at half maximal response across the cortex was narrower for SI-VASO than for SE-BOLD (1.7 mm vs. 2.5 mm, respectively), suggesting that SI-VASO is better localized to neuronally active sites than SE-BOLD fMRI. The magnitude of the SI-VASO change in the middle cortex was -1.45% with our experimental parameters, corresponding to a relative CBV change of approximately 8% when baseline CBV was assumed to be 5% in a two-compartment model. The signal response profile across the cortex, the calculated CBV change, and the time course of SI-VASO fMRI were similar to those of previously obtained CBV-weighted fMRI with contrast agent in the same animal model, suggesting that SI-VASO measures predominantly functional CBV responses.
Authors:
Tao Jin; Seong-Gi Kim
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2007-12-08
Journal Detail:
Title:  NeuroImage     Volume:  40     ISSN:  1053-8119     ISO Abbreviation:  Neuroimage     Publication Date:  2008 Mar 
Date Detail:
Created Date:  2008-02-11     Completed Date:  2008-04-23     Revised Date:  2013-11-07    
Medline Journal Info:
Nlm Unique ID:  9215515     Medline TA:  Neuroimage     Country:  United States    
Other Details:
Languages:  eng     Pagination:  59-67     Citation Subset:  IM    
Affiliation:
Department of Radiology, University of Pittsburgh, 3025 East Carson Street, University of Pittsburgh, Pittsburgh, PA 15203, USA. taj6@pitt.edu
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Vessels / anatomy & histology*,  physiology*
Blood Volume / physiology
Brain Mapping
Cats
Cerebral Cortex / anatomy & histology*,  blood supply,  physiology
Cerebrovascular Circulation / physiology*
Computer Simulation
Data Interpretation, Statistical
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Oxygen / blood*
Grant Support
ID/Acronym/Agency:
EB 003324/EB/NIBIB NIH HHS; EB 003375/EB/NIBIB NIH HHS; NS 44589/NS/NINDS NIH HHS; R01 EB003324/EB/NIBIB NIH HHS; R01 EB003324-08/EB/NIBIB NIH HHS; R01 EB003375/EB/NIBIB NIH HHS; R01 EB003375-10/EB/NIBIB NIH HHS; R01 NS044589/NS/NINDS NIH HHS; R01 NS044589-05A1/NS/NINDS NIH HHS; RR 17239/RR/NCRR NIH HHS; S10 RR017239/RR/NCRR NIH HHS; S10 RR017239-01/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
7782-44-7/Oxygen
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Parallel transport in diffeomorphisms distinguishes the time-dependent pattern of hippocampal surfac...
Next Document:  The radiation of microhylid frogs (Amphibia: Anura) on New Guinea: a mitochondrial phylogeny reveals...