Mismatched perfusion defects on routine ventilation‐perfusion scans after lung transplantation
Bibliographic record
Abstract
BACKGROUND: Incidental pulmonary embolism (PE) is a challenging entity with unclear treatment implications. Our program performs routine ventilation-perfusion (VQ) scans at 3-months post-transplant to establish airway and vascular function. We sought to determine the prevalence and prognostic implications of mismatched perfusion defects (MMPD) found on these studies, hypothesizing they would be associated with a benign prognosis. METHODS: We studied VQ scans obtained routinely at 3-months post-transplant from double lung transplant recipients 2005-2016 for studies with MMPD interpreted as high or intermediate probability for PE. We tested the relationship between MMPD and 1-year survival via chi square testing, overall survival via Kaplan Meier analysis with log rank testing and peak forced expiratory volume in 1 second (FEV1) percent predicted via t-testing. RESULTS: Three hundred and seventy-three patients met inclusion criteria, of whom 35 (9%) had VQ scans with MMPDs interpreted by radiologists as high or intermediate probability for PE. Baseline recipient and donor characteristics were similar between groups. Seven patients (20%) in the MMPD group were treated with therapeutic anticoagulation. Patients with MMPD had similar 1-year survival (100% vs. 98%, P = 1.00), overall survival (log rank P = .90) and peak FEV1% predicted (94% [SD 20%] vs. 92% [SD 21%]; P = .58). Anticoagulation did not affect these relationships. CONCLUSION: Mismatched perfusion defects on routine post-transplant VQ scan were not associated with a difference in survival or lung function. A conservative approach to these changes may be a viable option in the absence of other anticoagulation indications.
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 | 0.001 | 0.006 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".