Three-Dimensional Computed Tomography Measurements of Pulmonary Artery Volumes: Development and Application
Bibliographic record
Abstract
Chronic obstructive pulmonary disease (COPD) is a major contributor to hospitalizations and healthcare costs in North America. While the hallmark of COPD is airflow limitation, it is also associated with abnormalities of the cardiovascular system. Enlargement of the pulmonary artery (PA) is a morphological marker of pulmonary hypertension, and was previously shown to predict acute exacerbations using a one-dimensional (1D) diameter measurement of the main PA. We hypothesized that a three-dimensional (3D) quantification of PA size would be more sensitive than 1D methods and encompass morphological changes along the entire central PA. Hence, we developed a 3D measurement of the main (MPA), left (LPA) and right (RPA) pulmonary arteries as well as total PA volume (TPA) volume from thoracic x-ray computed tomography (CT) imaging. Three observers performed five repeated measurements for 15 ex-smokers. There was a strong agreement (r2 = 0.76) between PA volume and PA diameter measurements, which was used as the gold standard. Intra-rater measurement reproducibility was evaluated by calculating the coefficient of variation (CV) using five rounds of measurements and revealed excellent agreement (CV < 8%) between measurements. Inter-rater measurement variability was also evaluated using intraclass correlation analysis which revealed strong agreement (ICCMPA=0.98) between observers.\nIn an application of this tool, we sought to explore the relationship between PA volumes and lung structure-function as determined by spirometry, hyperpolarized helium-3 magnetic resonance imaging (MRI) and CT in 124 ex-smokers, with (n=68) and without (n=56) airflow limitation, and in a control group of 35 healthy never-smokers. We observed significantly greater MPA (p=.014), RPA (p=.001) and TPA (p=.003) volumes in ex-smokers with airflow limitation when compared to ex-smokers without airflow limitation. We also observed significantly greater PA volumes in both ex-smoker subgroups when compared with the never-smoker control group. Modest but significant correlations were observed for PA volumes and measurements of lung structure and function. However, this was not observed when analyzing ex-smokers with airflow limitation alone, suggesting that pulmonary artery enlargement may occur secondary to COPD in our subject group. Multivariate zero-inflated Poisson regression analysis revealed TPA volume to be a significant (p=.03) predictor of acute exacerbations of COPD.\nIn conclusion, we developed a reproducible technique for quantifying the volume of the PA. We showed that pulmonary artery enlargement may be secondary to COPD in our subject group. We also showed that total pulmonary artery volume was a significant predictor of COPD exacerbations and could be considered as a biomarker for predicting the occurrence of exacerbation events. Automated measurements of pulmonary artery abnormalities once developed, can be used to further evaluate healthy volunteers and patients with COPD.
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 | 0.003 | 0.008 |
| Meta-epidemiology (narrow) | 0.000 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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 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".