Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/11474
Title: Moving beyond a single perfusion threshold to define penumbra: a novel probabilistic mismatch definition.
Authors: Nagakane, Yoshinari;Christensen, Soren;Ogata, Toshiyasu;Churilov, Leonid;Ma, Henry K;Parsons, Mark W;Desmond, Patricia M;Levi, Christopher R;Butcher, Kenneth S;Davis, Stephen M;Donnan, Geoffrey A
Institutional Author: EPITHET Investigators
Affiliation: National Stroke Research Institute, Florey Neuroscience Institutes, Austin Health, University of Melbourne, Victoria 3053, Australia. gdonnan@unimelb.edu.au
Issue Date: 12-Apr-2012
Citation: Stroke; A Journal of Cerebral Circulation 2012; 43(6): 1548-55
Abstract: The mismatch lesion volumes defined by perfusion-weighted imaging exceeding diffusion-weighted imaging have been used as a marker of ischemic penumbral tissue. Defining the perfusion lesion by thresholding has shown promise as a practical tool; several positron emission tomography studies have indicated a more probabilistic relationship between perfusion and infarction. Here, we used a randomized controlled trial dataset of tissue-type plasminogen activator 3 to 6 hours after stroke to: (1) quantify the relationship between severity of hypoperfusion (measured by Tmax) and risk of infarction; (2) exploit this relationship to present a novel definition of mismatch based on infarct probabilities rather than dichotomies; and (3) examine the treatment response in the subgroup of patients with mismatch by the new definition.Patients from the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) were included. Baseline perfusion-weighted imaging and 90-day T2-weighted imaging were coregistered. Perfusion-weighted imaging lesion volumes were divided into 10 Tmax delay strata, and infarct risk was defined as the fraction of the tissue at a given Tmax strata that progressed to infarction by day 90.Sixty-two patients were studied. Infarct risk was an increasing function of Tmax for all subgroups, including the whole cohort. The probabilistic approach outperformed all Tmax thresholds, with exception of the Tmax ≥ 10 threshold, for which it was only favored by a trend.Infarct risk and treatment effect increased with severity of perfusion abnormalities. This suggests that a severity-weighted mismatch definition may define penumbral tissue more accurately.
Internal ID Number: 22499579
URI: http://ahro.austin.org.au/austinjspui/handle/1/11474
DOI: 10.1161/STROKEAHA.111.643932
URL: http://www.ncbi.nlm.nih.gov/pubmed/22499579
Type: Journal Article
Subjects: Adult
Aged
Aged, 80 and over
Cerebral Infarction.diagnosis.etiology.physiopathology
Female
Fibrinolytic Agents.administration & dosage
Humans
Magnetic Resonance Angiography
Male
Middle Aged
Positron-Emission Tomography
Risk Factors
Stroke.complications.diagnosis.drug therapy.physiopathology
Time Factors
Tissue Plasminogen Activator.administration & dosage
Appears in Collections:Journal articles

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