Chronic Obstructive Pulmonary Disease: Quantification of Bronchodilator Effects by Using Hyperpolarized He MR Imaging
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Bibliographic record
Abstract
PURPOSE: To evaluate short-acting bronchodilator effects in chronic obstructive pulmonary disease (COPD) by using hyperpolarized helium 3 (³He) magnetic resonance (MR) imaging, spirometry, and plethysmography. MATERIALS AND METHODS: Fourteen ex-smokers with COPD provided written informed consent to a local ethics board-approved and Health Insurance and Portability Accountability Act-compliant protocol and underwent hyperpolarized ³He and hydrogen 1 MR imaging, spirometry, and plethysmography before and a mean of 25 minutes ± 2 (standard deviation) after administration of 400 μg salbutamol. Distribution of ³He gas was evaluated by using semiautomated segmentation of ³He voxel intensities, where cluster 1 represented regions of signal void or ventilation defect volume (VDV), and clusters 2-5 (C2-C5) represented gradations of signal intensity from hypointensity (C2) to hyperintensity (C5). ³He ventilation defect percentage (VDP) was calculated as VDV normalized to the thoracic cavity volume. Comparisons of pre- and post-salbutamol means were performed by using a two-way mixed-design repeated measures analysis of variance, and comparisons of the magnitude of the treatment effect between pulmonary function and ³He MR imaging measurements were performed by using effect size (ES) calculations. The relationships between pulmonary function and ³He MR imaging findings were determined by using Spearman correlation coefficients. RESULTS: After salbutamol administration, there were significant changes in forced expiratory volume in 1 second (FEV₁) (P = .001), total lung capacity (P = .04), and functional residual capacity (P = .03), as well as VDP (P < .0001) and ³He gas distribution (C2, P = .01; C3, P = .03; C4, P < .0001; and C5, P = .02). Treatment ES was greater for ³He VDP than for FEV(1) (0.50 vs 0.22). There was a significant correlation between baseline VDP and post-salbutamol FEV₁ change (r = -0.77, P = .001). Although five patients were classified as bronchodilator responders and nine patients were classified as bronchodilator nonresponders according to American Thoracic Society and European Respiratory Society criteria, there was no significant difference in the magnitude of the ³He MR imaging changes after salbutamol administration between responder groups. CONCLUSION: ³He MR imaging depicted significant improvements in the distribution of ³He gas after bronchodilator therapy in ex-smokers with COPD with and those without clinically important changes in FEV₁.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it