Influence of 100% and 40% oxygen on penumbral blood flow, oxygen level, and T2*-weighted MRI in a rat stroke model

Tracey A Baskerville, Graeme A Deuchar, Christopher McCabe, Craig A Robertson, William M Holmes, Celestine Santosh, I Mhairi Macrae

Research output: Contribution to journalArticle

19 Citations (Scopus)


Accurate imaging of the ischemic penumbra is a prerequisite for acute clinical stroke research. T(2)(*) magnetic resonance imaging (MRI) combined with an oxygen challenge (OC) is being developed to detect penumbra based on changes in blood deoxyhemoglobin. However, inducing OC with 100% O(2) induces sinus artefacts on human scans and influences cerebral blood flow (CBF), which can affect T(2)(*) signal. Therefore, we investigated replacing 100% O(2) OC with 40% O(2) OC (5 minutes 40% O(2) versus 100% O(2)) and determined the effects on blood pressure (BP), CBF, tissue pO(2), and T(2)(*) signal change in presumed penumbra in a rat stroke model. Probes implanted into penumbra and contralateral cortex simultaneously recorded pO(2) and CBF during 40% O(2) (n=6) or 100% O(2) (n=8) OC. In a separate MRI study, T(2)(*) signal change to 40% O(2) (n=6) and 100% O(2) (n=5) OC was compared. Oxygen challenge (40% and 100% O(2)) increased BP by 8.2% and 18.1%, penumbra CBF by 5% and 15%, and penumbra pO(2) levels by 80% and 144%, respectively. T(2)(*) signal significantly increased by 4.56% ± 1.61% and 8.65% ± 3.66% in penumbra compared with 2.98% ± 1.56% and 2.79% ± 0.66% in contralateral cortex and 1.09% ± 0.82% and -0.32% ± 0.67% in ischemic core, respectively. For diagnostic imaging, 40% O(2) OC could provide sufficient T(2)(*) signal change to detect penumbra with limited influence in BP and CBF.

Original languageEnglish
Pages (from-to)1799-1806
Number of pages8
JournalJournal of Cerebral Blood Flow and Metabolism
Issue number8
Early online date11 May 2011
Publication statusPublished - Aug 2011


  • animals
  • blood pressure
  • cerebrovascular circulation
  • diagnostic imaging
  • disease models, animal
  • magnetic resonance imaging
  • oxygen
  • rats
  • stroke


Dive into the research topics of 'Influence of 100% and 40% oxygen on penumbral blood flow, oxygen level, and T2*-weighted MRI in a rat stroke model'. Together they form a unique fingerprint.

Cite this