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Record W2301996504 · doi:10.1161/str.43.suppl_1.a2674

Abstract 2674: DWI Reversal is associated with Small Infarct Volume and Early Reperfusion in Patients with TIA and Minor Stroke. Data from VISION and CATCH study groups

2012· article· en· W2301996504 on OpenAlexaff
Negar Asdaghi, Jonathan I Coulter, Jayish Modi, Abdul Qazi, Mayank Goyal, Kenneth Butcher, Michael D. Hill, Andrew M. Demchuk, Shelagh B. Coutts

Bibliographic record

VenueStroke · 2012
Typearticle
Languageen
FieldMedicine
TopicMRI in cancer diagnosis
Canadian institutionsUniversity of AlbertaUniversity of CalgaryCalgary Laboratory Services
Fundersnot available
KeywordsMedicinePenumbraModified Rankin ScaleFluid-attenuated inversion recoveryStroke (engine)Nuclear medicineProspective cohort studyMagnetic resonance imagingDiffusion MRIPopulationPerfusionLesionRadiologyCardiologyInternal medicineIschemic strokeSurgeryIschemia

Abstract

fetched live from OpenAlex

Introduction: One-third of patients with TIA and minor ischemic stroke (MIS) have evidence of ischemic penumbra, defined as hypoperfused regions that have not been irreversibly damaged. Diffusion weighted Imaging (DWI) lesions are thought to represent irreversibly damaged tissue. DWI reversal therefore has implications in accurate estimation of penumbra. We aimed to determine the rate of DWI reversal in this population. Methods: Patients with TIA/MIS (NIH Stroke Scale ≤ 3) were prospectively enrolled and imaged within 24 hours of symptom onset as part of two prospective imaging cohorts. Patients were included if their baseline modified Rankin scale (mRS) score was ≤1. All patients were followed clinically for 3 months and had a repeat MRI either at day 30 or 90. Baseline diffusion and perfusion lesions and follow-up FLAIR final infarct volumes were measured. Results: 418 patients were included; 55.5% had DWI lesions and 37% had PWI (Tmax+2s delay) deficits at baseline. A total of 337 (81%) patients had follow-up imaging. DWI reversal occurred in 22/192 (11.5%) of patients who had a diffusion lesion at baseline. The median time from symptom onset to follow-up imaging was not significantly different between those with or without DWI reversal (78.6 days, IQR=33.3 vs. 79.7 days, IQR= 59.4, p=0.65). The median DWI lesion volume was significantly smaller in those with reversal (0.27ml, IQR=0.75 ml) compared to those who did not reverse (1.45 ml, IQR=3.8 ml, p<0.001). Patients with concurrent perfusion deficits (Tmax+2s) were significantly less likely to have DWI reversal (6%) compared to those without evidence of tissue hypoperfusion (20%; p=0.003). DWI reversal occurred in 4% of patients with penumbral patterns ((Tmax+2s)-DWI) and 18% of those without penumbra (p=0.003).Severity of hypoperfusion defined as greater prolongation of Tmax (+2,+4, +6, +8s) did not affect the likelihood of DWI reversal (linear trend p=0.147). No patient with DWI reversal had a mRS of ≥2 at 90 day, compared to 19% of those with evidence of infarction on follow-up imaging (p= 0.02). Conclusion: DWI reversal is common in patients with TIA/MIS and is more likely to occur in those with smaller baseline lesions without concurrent tissue hypoperfusion. DWI reversal therefore should not have a significant effect on the accuracy of penumbra definition. These data suggest early reperfusion is correlated with DWI reversal and better clinical outcome as measured by mRS.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.002
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.003
Threshold uncertainty score0.009

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.002
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0000.000
Scholarly communication0.0010.000
Open science0.0000.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0030.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.024
GPT teacher head0.263
Teacher spread0.239 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations0
Published2012
Admission routes1
Has abstractyes

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