Document Detail


T2*-weighted magnetic resonance imaging with hyperoxia in acute ischemic stroke.
MedLine Citation:
PMID:  20582987     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: We describe the first clinical application of transient hyperoxia ("oxygen challenge") during T2*-weighted magnetic resonance imaging (MRI), to detect differences in vascular deoxyhemoglobin between tissue compartments following stroke. METHODS: Subjects with acute ischemic stroke were scanned with T2*-weighted MRI and oxygen challenge. For regions defined as infarct core (diffusion-weighted imaging lesion) and presumed penumbra (perfusion-diffusion mismatch [threshold = T(max) > or =4 seconds], or regions exhibiting diffusion lesion expansion at day 3), T2*-weighted signal intensity-time curves corresponding to the duration of oxygen challenge were generated. From these, the area under the curve, gradient of incline of the signal increase, time to maximum signal, and percentage signal change after oxygen challenge were measured. RESULTS: We identified 25 subjects with stroke lesions >1ml. Eighteen subjects with good quality T2*-weighted signal intensity-time curves in the contralateral hemisphere were analyzed. Curves from the diffusion lesion had a smaller area under the curve, percentage signal change, and gradient of incline, and longer time to maximum signal (p < 0.05, n = 17) compared to normal tissue, which consistently showed signal increase during oxygen challenge. Curves in the presumed penumbral regions (n = 8) showed varied morphology, but at hyperacute time points (<8 hours) showed a tendency to greater percentage signal change. INTERPRETATION: Differences in T2*-weighted signal intensity-time curves during oxygen challenge in brain regions with different pathophysiological states after stroke are likely to reflect differences in deoxyhemoglobin concentration, and therefore differences in metabolic activity. Despite its underlying complexities, this technique offers a possible novel mode of metabolic imaging in acute stroke.
Authors:
Krishna A Dani; Celestine Santosh; David Brennan; Christopher McCabe; William M Holmes; Barrie Condon; Donald M Hadley; I Mhairi Macrae; Martin Shaw; Keith W Muir
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Annals of neurology     Volume:  68     ISSN:  1531-8249     ISO Abbreviation:  Ann. Neurol.     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-07-01     Completed Date:  2010-07-20     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7707449     Medline TA:  Ann Neurol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  37-47     Citation Subset:  IM    
Affiliation:
Division of Clinical Neurosciences, University of Glasgow, Institute of Neurological Sciences, Southern General Hospital, Glasgow, UK.
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MeSH Terms
Descriptor/Qualifier:
Acute Disease
Aged
Aged, 80 and over
Brain / pathology*
Brain Ischemia / pathology*
Diffusion
Diffusion Magnetic Resonance Imaging / methods
Female
Functional Laterality
Humans
Hyperoxia / pathology*
Magnetic Resonance Imaging / methods*
Male
Middle Aged
Signal Processing, Computer-Assisted
Stroke / pathology*
Time Factors

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


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