scholarly journals A homological approach to a mathematical definition of pulmonary fibrosis and emphysema on computed tomography

2021 ◽  
Author(s):  
Naoya Tanabe ◽  
Shizuo Kaji ◽  
Susumu Sato ◽  
Tomoo Yokoyama ◽  
Tsuyoshi Oguma ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Fibrosis ◽  
Structural Changes ◽  
Persistent Homology ◽  
Three Dimensional ◽  
Connected Components ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Diffusion Capacity ◽  
Definition Of

Three-dimensional imaging is essential to evaluate local abnormalities and understand structure-function relationships in an organ. However, quantifiable and interpretable methods to localize abnormalities remain unestablished. Visual assessments are prone to bias, machine learning methods depend on training images, and the underlying decision principle is usually difficult to interpret. Here, we developed a homological approach to mathematically define emphysema and fibrosis in the lungs on computed tomography (CT). Using persistent homology, the density of homological features, including connected components, tunnels, and voids, was extracted from the volumetric CT scans of lung diseases. A pair of CT values at which each homological feature appeared (birth) and disappeared (death) was computed by sweeping the threshold levels from higher to lower CT values. Consequently, fibrosis and emphysema were defined as voxels with dense voids having a longer lifetime (birth-death difference) and voxels with dense connected components having a lower birth, respectively. In an independent dataset including subjects with idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), and combined pulmonary fibrosis and emphysema (CPFE), the proposed definition enabled accurate segmentation with comparable quality to deep learning in terms of Dice coefficients. Persistent homology-defined fibrosis was closely associated with physiological abnormalities such as impaired diffusion capacity and long-term mortality in subjects with IPF and CPFE, and persistent homology-defined emphysema was associated with impaired diffusion capacity in subjects with COPD. The present persistent homology-based evaluation of structural abnormalities could help explore the clinical and physiological impacts of structural changes and morphological mechanisms of disease progression.

Evaluation of cigarette smoke-induced emphysema in mice using quantitative micro-computed tomography

2015 ◽  
Vol 308 (10) ◽  
pp. L1039-L1045 ◽  
Author(s):  
Mamoru Sasaki ◽  
Shotaro Chubachi ◽  
Naofumi Kameyama ◽  
Minako Sato ◽  
Mizuha Haraguchi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cigarette Smoke ◽  
Structural Changes ◽  
Chronic Obstructive ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Obstructive Pulmonary Disease ◽  
Calculated Volume ◽  
Lung Ct ◽  
Time Point

Chronic cigarette smoke (CS) exposure provokes variable changes in the lungs, and emphysema is an important feature of chronic obstructive pulmonary disease. The usefulness of micro-computed tomography (CT) to assess emphysema in different mouse models has been investigated, but few studies evaluated the dynamic structural changes in a CS-induced emphysema mouse model. A novel micro-CT technique with respiratory and cardiac gating has resulted in high-quality images that enable processing for further quantitative and qualitative analyses. Adult female C57BL/6J mice were repeatedly exposed to mainstream CS, and micro-CT scans were performed at 0, 4, 12, and 20 wk. Emphysema was also histologically quantified at each time point. Air-exposed mice and mice treated with intratracheal elastase served as controls and comparisons, respectively. End-expiratory lung volume, corresponding to functional residual volume, was defined as the calculated volume at the phase of end-expiration, and it evaluated air trapping. The end-expiratory lung volumes of CS-exposed mice were significantly larger than those of air controls at 12 and 20 wk, which was in line with alveolar enlargement and destruction by histological quantification. However, CS exposure neither increased low attenuation volume nor decreased the average lung CT value at any time point, unlike the elastase-instilled emphysema model. CS-exposed mice had rather higher average lung CT values at 4 and 12 wk. This is the first study characterizing a CS-induced emphysema model on micro-CT over time in mice. Moreover, these findings extend our understanding of the distinct pathophysiology of CS-induced emphysema in mice.

scholarly journals Differences in regional air trapping in current smokers with normal spirometry

2017 ◽  
Vol 49 (1) ◽  
pp. 1600345 ◽  
Author(s):  
Reza Karimi ◽  
Göran Tornling ◽  
Helena Forsslund ◽  
Mikael Mikko ◽  
Åsa M. Wheelock ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Structural Changes ◽  
Forced Expiratory Volume ◽  
Wall Thickening ◽  
Chronic Obstructive ◽  
Air Trapping ◽  
Obstructive Pulmonary Disease ◽  
Never Smokers ◽  
Detection Of Smoking ◽  
Specific Manifestation

We investigated regional air trapping on computed tomography in current smokers with normal spirometry. It was hypothesised that presence of regional air trapping may indicate a specific manifestation of smoking-related changes.40 current smokers, 40 patients with chronic obstructive pulmonary disease (COPD), and 40 healthy never- smokers underwent computed tomography scans. Regional air trapping was assessed on end-expiratory scans and emphysema, micronodules and bronchial wall thickening on inspiratory scans. The ratio of expiratory and inspiratory mean lung attenuation (E/I) was calculated as a measure of static (fixed) air trapping.Regional air trapping was present in 63% of current smokers, in 45% of never smokers and in 8% of COPD patients (p<0.001). Current smokers with and without regional air trapping had E/I ratio of 0.81 and 0.91, respectively (p<0.001). Forced expiratory volume in 1 s (FEV1) was significantly higher and emphysema less frequent in current smokers with regional air trapping.Current smokers with regional air trapping had higher FEV1 and less emphysema on computed tomography. In contrast, current smokers without regional air trapping resembled COPD. Our results highlight heterogeneity among smokers with normal spirometry and may contribute to early detection of smoking related structural changes in the lungs.

scholarly journals Sex-related differences in bronchial parameters and pulmonary function test results in patients with chronic obstructive pulmonary disease based on three-dimensional quantitative computed tomography

2017 ◽  
Vol 46 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Yan Li ◽  
Yong-liang Dai ◽  
Nan Yu ◽  
You-min Guo
Keyword(s):  
Computed Tomography ◽  
Chronic Obstructive Pulmonary Disease ◽  
Smoking Cessation ◽  
Pulmonary Function ◽  
Pulmonary Disease ◽  
Quantitative Computed Tomography ◽  
Three Dimensional ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease

Objective This study was performed to evaluate the effect of sex on bronchial parameters and the predicted forced expiratory volume in 1 s expressed as a percentage of the forced vital capacity (FEV1% pred) on pulmonary function testing. Methods The data of 359 patients with chronic obstructive pulmonary disease (COPD) with available FEV1% pred and computed tomography (CT) images were retrospectively reviewed. FACT-Digital lung TM software (DeXin, Xi’an, China) was used to perform fully automated three-dimensional CT quantitative measurements of the bronchi. Generation 5 to 7 bronchi were measured, and the parameters analyzed were the lumen diameter (LD), wall thickness (WT), lumen area (LA), and WA% [WA / (WA + LA) × 100%]. Results In the smoking, smoking cessation, and nonsmoking groups, women had a significantly larger WA% and smaller LD, WT, and LA than men. The FEV1% pred was significantly lower in women than men in the smoking and smoking cessation groups. The FEV1% pred was significantly higher in women than men in the nonsmoking group. Conclusion Sex-related differences may partially explain why smoking women experience more severe pulmonary function impairment than men among patients with COPD.

scholarly journals Periostin and closing volume in combined pulmonary fibrosis and emphysema

2020 ◽  
Author(s):  
Fernando Medeiros Anselmo ◽  
Cláudia Henrique da Costa ◽  
Luciana Silva Rodrigues ◽  
Thaís Porto Amadeu ◽  
Mariana Martins de Athaide ◽  
...  
Keyword(s):  
Idiopathic Pulmonary Fibrosis ◽  
Pulmonary Fibrosis ◽  
Pulmonary Function Tests ◽  
Cross Sectional Study ◽  
Chronic Obstructive ◽  
Closing Volume ◽  
Cross Sectional ◽  
Obstructive Pulmonary Disease ◽  
Diffusion Capacity ◽  
Characterization Methods

Abstract Background Combined pulmonary fibrosis and emphysema (CPFE) is an entity characterized by the presence of emphysema in upper lobes and fibrosis in lower lobes. Due to the presence of the two diseases concomitantly, it may be difficult to diagnose. This study aims at a better understanding of this entity and proposes biological markers (functional and biochemical) that help in this characterization. Methods A prospective, observational, cross-sectional study was carried out at a reference center. Pulmonary function tests (spirometry, CO-diffusion capacity, plethysmography and single-maneuver nitrogen washout test - SBWN 2 ) and biochemical markers (periostin, mucin-16, PDGF-BB and TGF-β 1 ) were measured in groups of patients: idiopathic pulmonary fibrosis, CPFE and chronic obstructive pulmonary disease (COPD). Results Variables derived from SBWN 2 - closing volume (CV) / vital capacity (VC) (%) and closing capacity (CC) / total lung capacity (TLC) (%) - were found to be higher in the CPFE group compared to the Idiopathic pulmonary fibrosis (IPF) group (CV/VC%: 0.25 (0.12 – 11.01) and 13.05 (0.21 – 20.73); p = 0.005; CC/TLC%: 30.1 (22.4 – 37.47) and 33.69 (32.05 – 41.98); p = 0.03, respectively). Periostin was higher in the CPFE group than in the other groups [CPFE: 66.74 (45.21 – 90.5), IPF: 43.81 (31.97 – 56.18), COPD: 40.08 (20.66 – 50.81); p = 0.0002], and mucin-16 was higher in the IPF group than in the CPFE group [CPFE: 13.59 (4.16 – 28.16); IPF: 71.94 (40.46 - 164); COPD: 25.85 (9.27 – 30.29); p = 0.02]. Conclusions Findings show that CPFE presents different functional and biochemical characteristics than IPF, including higher CV/VC%, CC/TLC% and periostin, whereas mucin-16 was higher in the IPF.

scholarly journals Computed tomography total airway count predicts progression to COPD in at risk smokers

2021 ◽  
pp. 00307-2021
Author(s):  
Miranda Kirby ◽  
Benjamin M. Smith ◽  
Naoya Tanabe ◽  
James C. Hogg ◽  
Harvey O. Coxson ◽  
...  
Keyword(s):  
Computed Tomography ◽  
At Risk ◽  
Structural Changes ◽  
Population Based ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Wall Area ◽  
Ct Measurements ◽  
Airway Tree

There is limited understanding of how to identify people at high risk of developing chronic obstructive pulmonary disease (COPD). Our objective was to investigate the association between computed tomography (CT) total airway count (TAC) and incident COPD over 3-years among ever-smokers from the population-based Canadian Cohort Obstructive Lung Disease (CanCOLD) study.CT and spirometry were acquired in ever-smokers at baseline; spirometry was repeated at 3-year follow-up. CT TAC was generated by summing all airway segments in the segmented airway tree (VIDA Diagnostics, Inc.). CT airway wall area, wall thickness for a theoretical airway with 10 mm perimeter (Pi10), and low attenuation areas below −856HU (LAA856) were also measured. Logistic and mixed effects regression models were constructed to determine the association for CT measurements with development of COPD and FEV1/FVC decline, respectively.Among 316 at risk participants evaluated at baseline (65±9 years, 40% female, 18±19 pack-years), incident COPD was detected in 56 participants (18%) over a median 3.1±0.6 years of follow-up. Among CT measurements, only TAC was associated with incident COPD (p=0.03), where a 1-sd decrement in TAC increased the odds ratio for incident COPD by a factor of two. In a multivariable linear regression model, reduced TAC was significantly associated with greater longitudinal FEV1/FVC decline (p=0.03), but no other measurements were significant.CT TAC predicts incident COPD in at risk smokers, indicating that smokers exhibit early structural changes associated with COPD prior to abnormal spirometry.

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