Abstract T P53: Regional Vascular Status On Multi-phase CTA Correlates Well With Regional CT Perfusion Estimates And Final Tissue Fate
Bibliographic record
Abstract
Introduction: Multi-phase CTA (mCTA) is a new imaging tool that generates time resolved images of contrast filling-in and washout within pial vessels in ischemic brain regions. In this study, we seek to demonstrate criterion and predictive validity of this imaging tool regionally by comparing vascular status as assessed using mCTA with CT perfusion estimates and with final tissue fate. Methods: Data is from PRove-IT, an ongoing multi-national prospective study that seeks to understand the utility of multi-modal imaging in the triage of acute ischemic stroke patients. Only patients with M1-MCA occlusions were included for the analysis. “Delay” in maximal pial vessel enhancement, “Extent” of maximal pial vessel enhancement and degree of “Washout” of contrast within these pial vessels was each graded on a 3-point scale in each of the 5 ASPECTS regions (M2-6)(Fig 1). CBF, CBV, MTT, T Max and T0 values were calculated within these same ASPECTS regions on CTP. Reperfusion status was assessed regionally using the Kim’s template. Final tissue fate per region was determined on 24 hr MR/CT. Results: We included 45 patients (225 ASPECTS regions) in the study. Specific parameters on mCTA correlated with specific perfusion estimates on CTP [Delay and T0 time (Kruskal-Wallis p=0.001), Washout and MTT (p<0.001), Extent and CBV (p<0.001)] regionally. On multivariable linear regression, Washout (p=0.04) and Extent grade (p<0.001) in each region were independently associated with ipsi-regional CBF. Classification and regression tree analysis (CART) discriminated between regional CBF thresholds ranging from <7ml/100gm/min to >15ml/100gm/min using a combined “Washout+Extent” grade on mCTA. In the early reperfusers, this combined “Washout+Extent” grade was related significantly with tissue fate regionally (Fisher’s p=0.04). Conclusion: Regional vascular status on mCTA provides similar information to CTP estimates and is capable of predicting final tissue fate regionally.
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 imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".