Five-year MRI study of ventilation heterogeneity in asthma
Bibliographic record
Abstract
Introduction: Pulmonary functional MRI has shown that ventilation abnormalities in asthma are not diffuse, but highly focal and temporally-persistent, however the spatial persistence over long periods of time is unknown. Objective: To longitudinally evaluate asthmatics to determine the long-term pattern of MRI ventilation defects and their relationship to asthma control and beta-agonist reversibility. We hypothesized that ventilation defects would enlarge and become more numerous and this would be related to loss of reversibility and control. Methods: Patients with a clinical-diagnosis of asthma were evaluated using hyperpolarised 3He MRI at baseline, post-methacholine and post-bronchodilator (BD) at baseline (V1) and pre- and post-BD at least 60-months later (V2). Results: For this interim analysis, 8 patients with mild-moderate asthma were evaluated at V1 and 72±6 months later. Ventilation defect percent (VDP) at V1 was related to asthma control at V2 (r=0.78, p=0.02) and a greater worsening in VDP was related to greater BD-response at V2 (r=-0.74, p=0.04). For two patients (25%), at V2 there was MRI evidence of a greater number of and enlarged ventilation defects in the same spatial location as at baseline and post-methacholine in V1. For all patients, the spatial-distribution of ventilation and ventilation-defects were qualitatively similar at follow-up such that these persisted in the same spatial locations over the follow-up period. Conclusion: Ventilation defects persisted in the same spatial locations after 72 months and were related to worse asthma control at follow-up. This preliminary result suggests that ventilation abnormalities in asthma are persistent, non-random, and predictive of future outcomes.
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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 | 0.001 | 0.001 |
| 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 | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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.
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".