COPD: Do Imaging Measurements of Emphysema and Airway Disease Explain Symptoms and Exercise Capacity?
Bibliographic record
Abstract
PURPOSE: To determine the role of imaging measurements of emphysema and airway disease in determining chronic obstructive pulmonary disease (COPD) symptoms and exercise limitation in patients with COPD, particularly in patients with mild-to-moderate disease. MATERIALS AND METHODS: Participants (n = 116) with Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade U (unclassified) or grade I-IV COPD provided informed consent to an ethics board-approved HIPAA-compliant protocol and underwent spirometry and plethysmography, completed the St George's Respiratory Questionnaire (SGRQ), completed a 6-minute walk test for the 6-minute walk distance (6MWD), and underwent hyperpolarized helium 3 ((3)He) magnetic resonance (MR) imaging and computed tomography (CT). Emphysema was estimated by using the MR imaging apparent diffusion coefficient (ADC) and the relative area of the CT attenuation histogram with attenuation of -950 HU or less (RA950). Airway disease was measured by using the CT airway wall thickness of airways with an internal perimeter of 10 mm and total airway count. Ventilation defect percentage at (3)He MR imaging was used to measure ventilation. Multivariable regression models for the 6MWD and SGRQ symptom subscore were used to evaluate the relationships between physiologic and imaging measurements. RESULTS: Multivariate modeling for the 6MWD in 80 patients with GOLD grade U-II COPD showed that ADC (β = 0.34, P = .04), diffusing capacity of the lung for carbon monoxide (β = 0.60, P = .0008), and residual volume/total lung capacity (β = -0.26, P = .02) were significant variables, while forced expiratory volume in 1 second (FEV1) and airway disease measurements were not. In 36 patients with GOLD grade III or IV disease, FEV1 (β = 0.48, P = .01) was the only significant contributor in a multivariate model for 6MWD. MR imaging emphysema measurements also made the greatest relative contribution to symptoms in patients with milder (GOLD grade U-II) COPD (ADC: β = 0.60, P = .005; RA950: β = -0.52, P = .02; FEV1: β = -0.45, P = .0002) and in grade III or IV disease (ADC: β = 0.95, P = .01; RA950: β = -0.62, P = .07; airway count: β = -0.49, P = .01). CONCLUSION: In patients with mild-to-moderate COPD, MR imaging emphysema measurements played a dominant role in the expression of exercise limitation, while both CT and MR imaging measurements of emphysema explained symptoms.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".