Bibliographic record
Abstract
ASPECTS (Alberta Stroke Program Early CT Score) is an irregular scoring systemthat reads out as 10 to 0 points. It was originally conceived to reflect acute MCA (middle cerebral artery) territory infarct volume on (plain) CT, but it is equally applicable to and testable by MRI.Background material prepares the reader by explaining pertinent measurement principles and ASPECTS’s genesis, definitions, claims, and quirks. This report investigates ASPECTS as a volume surrogate without independently advocating for or against the therapies it might help plan.Method: The original authors of four publications provided their unpublished primary numerical data for further analysis. A CT study expands on the ACCESS database, which compares ASPECTS with two other subjective infarct scales: the legacy 1/3 MCA estimate and the multivariate IST-3 scale. An MRI study pools three diffusion-weighted (DWI) series as a patient-level meta-analysis unifying their comparisons of ASPECTS to the volumes that were found by semiautomated measurement.CT results: ASPECTS is unreliable, showing wide interrater variation with three quantifiable effects. It delivers little more than half as much entropy reduction as the IST-3 scale shows CT can support. Its large standard deviation (SD) takes up much of the scale width. Converting SD to a loss function with respect to a reference standard neuroradiologist gives an alarming weighted measure of error in ratings.MRI results: There are many-fold ranges of volume per ASPECTS and of ASPECTS per volume, causing sometimes large misclassifications one or both ways by any ASPECTS dichotomization. Looking past the ranges to averages, an estimate of 1/3 of the MCA territory corresponds best to ASPECTS cutting between 6 and 5 (6//5) and a volume of 65 mL (<1/4 of the average MCA territory).Discussion: There is already a simple, quick, and reliable manual volume measure (ABC/2, 2Sh/3). An attempt to salvage ASPECTS by reinterpreting its purpose does not hold up under scrutiny. ASPECTS can be replaced in stroke guidelines: the guideline cutting at ASPECTS 6//5 is consistent on average with the increasingly commonly stated, and better defined, 70 mL threshold. Arguments defending ASPECTS are rebutted by the evidence herein and by literature citations.Conclusion: ASPECTS subtracts value from the more objective direct volume measurements that are universally available by manual calculation and are becoming available by automatic software. ASPECTS inherently risks clinically significant misclassification (harm) for many patients.
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 | 0.048 | 0.129 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.009 | 0.010 |
| Science and technology studies | 0.001 | 0.006 |
| Scholarly communication | 0.005 | 0.005 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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".