Document Detail


The vascular mean transit time: a surrogate for the penumbra flow threshold?
MedLine Citation:
PMID:  21045862     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Depicting the salvageable tissue is increasingly used in the clinical setting following stroke. As absolute cerebral blood flow (CBF) is difficult to measure using perfusion magnetic resonance or computed tomography and has limitations as a penumbral marker, time-based variables, particularly the mean transit time (MTT), are routinely used as surrogates. However, a direct validation of MTT as a predictor of the penumbra threshold using gold-standard positron emission tomography (PET) is lacking. Using (15)O-PET data sets obtained from two independent acute stroke samples (N=7 and N=30, respectively), we derived areas under the curve (AUCs), optimal thresholds (OTs), and 90%-specificity thresholds (90%-Ts) from receiver operating characteristic curves for absolute MTT, MTT delay, and MTT ratio to predict three penumbra thresholds ('classic': CBF <20  mL/100  g per min; 'normalized': CBF ratio <0.5; and 'stringent': both CBF <20  mL/100  g per min and oxygen extraction fraction >0.55). In sample 1, AUCs ranged from 0.79 to 0.92, indicating good validity; OTs ranged from 7.8 to 8.3  seconds, 2.8 to 4.7  seconds, and 151% to 267% for absolute MTT, MTT delay, and MTT ratio, respectively, while as expected, 90%-Ts were longer. There was no significant difference between sample 1 and sample 2 for any of the above measurements, save for a single MTT parameter with a single penumbra threshold. These consistent findings from gold-standard PET obtained in two independent cohorts document that MTT is a very good surrogate to CBF for depicting the penumbra threshold.
Authors:
Emmanuel Carrera; P Simon Jones; Serge Iglesias; Joseph V Guadagno; Elizabeth A Warburton; Tim D Fryer; Franklin I Aigbirhio; Jean-Claude Baron
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-11-03
Journal Detail:
Title:  Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism     Volume:  31     ISSN:  1559-7016     ISO Abbreviation:  J. Cereb. Blood Flow Metab.     Publication Date:  2011 Apr 
Date Detail:
Created Date:  2011-04-01     Completed Date:  2011-05-27     Revised Date:  2012-04-02    
Medline Journal Info:
Nlm Unique ID:  8112566     Medline TA:  J Cereb Blood Flow Metab     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1027-35     Citation Subset:  IM    
Affiliation:
Department of Clinical Neurosciences, The Stroke Research Group, University of Cambridge, Cambridge, UK.
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MeSH Terms
Descriptor/Qualifier:
Aged
Aged, 80 and over
Blood Circulation Time
Cerebral Infarction / physiopathology,  radionuclide imaging
Cerebrovascular Circulation / physiology*
Cohort Studies
Data Interpretation, Statistical
Female
Humans
Male
Middle Aged
Positron-Emission Tomography
ROC Curve
Reperfusion
Risk Factors
Stroke / physiopathology*,  radionuclide imaging
Young Adult
Grant Support
ID/Acronym/Agency:
G0001219//Medical Research Council; G0500874//Medical Research Council

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


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