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Defining the ischemic penumbra using magnetic resonance oxygen metabolic index.

Publication ,  Journal Article
An, H; Ford, AL; Chen, Y; Zhu, H; Ponisio, R; Kumar, G; Shanechi, AM; Khoury, N; Vo, KD; Williams, J; Derdeyn, CP; Diringer, MN; Panagos, P ...
Published in: Stroke
April 2015

BACKGROUND AND PURPOSE: Penumbral biomarkers promise to individualize treatment windows in acute ischemic stroke. We used a novel magnetic resonance imaging approach that measures oxygen metabolic index (OMI), a parameter closely related to positron emission tomography-derived cerebral metabolic rate of oxygen utilization (CMRO2), to derive a pair of ischemic thresholds: (1) an irreversible-injury threshold that differentiates ischemic core from penumbra and (2) a reversible-injury threshold that differentiates penumbra from tissue not-at-risk for infarction. METHODS: Forty patients with acute ischemic stroke underwent magnetic resonance imaging at 3 time points after stroke onset: <4.5 hours (for OMI threshold derivation), 6 hours (to determine reperfusion status), and 1 month (for infarct probability determination). A dynamic susceptibility contrast method measured cerebral blood flow, and an asymmetrical spin echo sequence measured oxygen extraction fraction, to derive OMI (OMI=cerebral blood flow×oxygen extraction fraction). Putative ischemic threshold pairs were iteratively tested using a computation-intensive method to derive infarct probabilities in 3 tissue groups defined by the thresholds (core, penumbra, and not-at-risk tissue). An optimal threshold pair was chosen based on its ability to predict infarction in the core, reperfusion-dependent survival in the penumbra, and survival in not-at-risk tissue. The predictive abilities of the thresholds were then tested within the same cohort using a 10-fold cross-validation method. RESULTS: The optimal OMI ischemic thresholds were found to be 0.28 and 0.42 of normal values in the contralateral hemisphere. Using the 10-fold cross-validation method, median infarct probabilities were 90.6% for core, 89.7% for nonreperfused penumbra, 9.95% for reperfused penumbra, and 6.28% for not-at-risk tissue. CONCLUSIONS: OMI thresholds, derived using voxel-based, reperfusion-dependent infarct probabilities, delineated the ischemic penumbra with high predictive ability. These thresholds will require confirmation in an independent patient sample.

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Published In

Stroke

DOI

EISSN

1524-4628

Publication Date

April 2015

Volume

46

Issue

4

Start / End Page

982 / 988

Location

United States

Related Subject Headings

  • Stroke
  • Reproducibility of Results
  • Prognosis
  • Oxygen
  • Neurology & Neurosurgery
  • Middle Aged
  • Male
  • Magnetic Resonance Imaging
  • Humans
  • Female
 

Citation

APA
Chicago
ICMJE
MLA
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An, H., Ford, A. L., Chen, Y., Zhu, H., Ponisio, R., Kumar, G., … Lin, W. (2015). Defining the ischemic penumbra using magnetic resonance oxygen metabolic index. Stroke, 46(4), 982–988. https://doi.org/10.1161/STROKEAHA.114.008154
An, Hongyu, Andria L. Ford, Yasheng Chen, Hongtu Zhu, Rosana Ponisio, Gyanendra Kumar, Amirali Modir Shanechi, et al. “Defining the ischemic penumbra using magnetic resonance oxygen metabolic index.Stroke 46, no. 4 (April 2015): 982–88. https://doi.org/10.1161/STROKEAHA.114.008154.
An H, Ford AL, Chen Y, Zhu H, Ponisio R, Kumar G, et al. Defining the ischemic penumbra using magnetic resonance oxygen metabolic index. Stroke. 2015 Apr;46(4):982–8.
An, Hongyu, et al. “Defining the ischemic penumbra using magnetic resonance oxygen metabolic index.Stroke, vol. 46, no. 4, Apr. 2015, pp. 982–88. Pubmed, doi:10.1161/STROKEAHA.114.008154.
An H, Ford AL, Chen Y, Zhu H, Ponisio R, Kumar G, Shanechi AM, Khoury N, Vo KD, Williams J, Derdeyn CP, Diringer MN, Panagos P, Powers WJ, Lee J-M, Lin W. Defining the ischemic penumbra using magnetic resonance oxygen metabolic index. Stroke. 2015 Apr;46(4):982–988.

Published In

Stroke

DOI

EISSN

1524-4628

Publication Date

April 2015

Volume

46

Issue

4

Start / End Page

982 / 988

Location

United States

Related Subject Headings

  • Stroke
  • Reproducibility of Results
  • Prognosis
  • Oxygen
  • Neurology & Neurosurgery
  • Middle Aged
  • Male
  • Magnetic Resonance Imaging
  • Humans
  • Female