Dataset Information

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study.

ABSTRACT:

Background and objective

This study aimed to investigate whether quantitative lung vessel morphology determined by a new fully automated algorithm is associated with functional indices in idiopathic pulmonary fibrosis (IPF).

Methods

A total of 152 IPF patients had vessel volume, density, tortuosity and heterogeneity quantified from computed tomography (CT) images by a fully automated algorithm. Separate quantitation of vessel metrics in pulmonary arteries and veins was performed in 106 patients. Results were evaluated against readouts from lung function tests.

Results

Normalized vessel volume expressed as a percentage of total lung volume was moderately correlated with functional indices on univariable linear regression analysis: forced vital capacity (R² =?0.27, P -6 ), diffusion capacity for carbon monoxide (DL_CO ; R² =?0.12, P =?3?×?10^-5 ), total lung capacity (TLC; R² =?0.45, P -6 ) and composite physiologic index (CPI; R² =?0.28, P -6 ). Normalized vessel volume was correlated with vessel density but not with vessel heterogeneity. Quantitatively derived vessel metrics (and artery and vein subdivision scores) were not significantly linked with the transfer factor for carbon monoxide (K_CO ), and only weakly with DL_CO . On multivariable linear regression analysis, normalized vessel volume and vessel heterogeneity were independently linked with DL_CO , TLC and CPI indicating that they capture different aspects of lung damage. Artery-vein separation provided no additional information beyond that captured in the whole vasculature.

Conclusion

Our study confirms previous observations of links between vessel volume and functional measures of disease severity in IPF using a new vessel quantitation tool. Additionally, the new tool shows independent linkages of normalized vessel volume and vessel heterogeneity with functional indices. Quantitative vessel metrics do not appear to reflect vasculopathic damage in IPF.

SUBMITTER: Jacob J

PROVIDER: S-EPMC6519024 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

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Publications

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study.

Jacob Joseph J Pienn Michael M Payer Christian C Urschler Martin M Kokosi Maria M Devaraj Anand A Wells Athol U AU Olschewski Horst H

Respirology (Carlton, Vic.) 20190220 5

<h4>Background and objective</h4>This study aimed to investigate whether quantitative lung vessel morphology determined by a new fully automated algorithm is associated with functional indices in idiopathic pulmonary fibrosis (IPF).<h4>Methods</h4>A total of 152 IPF patients had vessel volume, density, tortuosity and heterogeneity quantified from computed tomography (CT) images by a fully automated algorithm. Separate quantitation of vessel metrics in pulmonary arteries and veins was performed i ...[more]

PMID: 30786325

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Project description:IntroductionGastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF). Mean nocturnal baseline impedance (MNBI) is a marker of esophageal mucosal integrity, whereas postreflux swallow-induced peristaltic wave (PSPW) index reflects esophageal chemical clearance. Both metrics offer novel ways to assess reflux burden on multichannel intraluminal impedance-pH testing (MII-pH), but their role in extraesophageal reflux remains unclear. We aimed to evaluate the relationship between these novel metrics and lung function decline in patients with IPF.MethodsAdults with IPF undergoing prelung transplant MII-pH were enrolled. All patients completed pulmonary function testing (PFT) at the time of MII-pH and at the 1-year follow-up. MNBI was calculated by averaging baseline impedance at three 10-minute intervals (1 AM/2 AM/3 AM). PSPW index was the proportion of all reflux episodes, followed by a peristaltic swallow within 30 seconds. Univariate (Student t-test/Pearson correlation) and multivariable (general linear regression) analyses were performed.ResultsOne hundred twenty-five subjects (mean age = 61.7 years, 62% men) were included. Forced expiratory volume in one second and forced vital capacity declined more significantly over 12 months in subjects with lower distal MNBI, proximal MNBI, and PSPW index (all P < 0.05). On multivariable analyses adjusting for age, sex, proton pump inhibitor use, and baseline lung function, distal MNBI (β = -10.86, P = 0.024; β = -8.03, P = 0.045), proximal MNBI (β = -13.5, P = 0.0068; β = -9.80, P = 0.025), and PSPW index (β = -18.1, P = 0.010; β = -12.55, P = 0.050) remained predictive of greater forced expiratory volume in one second and forced vital capacity decline.DiscussionLow distal MNBI, proximal MNBI, and PSPW index independently predicted more severe lung function decline over 1 year in patients with IPF. These impedance metrics may have prognostic value and support a role for reflux in IPF pathogenesis.

Project description:ObjectivesTo quantify the heterogeneity of fibrosis boundaries in idiopathic pulmonary fibrosis (IPF) using the Gaussian curvature analysis for evaluating disease severity and predicting survival.MethodsWe retrospectively included 104 IPF patients and 52 controls who underwent baseline chest CT scans. Normal lungs below - 500 HU were segmented, and the boundary was three-dimensionally reconstructed using in-house software. Gaussian curvature analysis provided histogram features on the heterogeneity of the fibrosis boundary. We analyzed the correlations between histogram features and the gender-age-physiology (GAP) and CT fibrosis scores. We built a regression model to predict diffusing capacity of carbon monoxide (DLCO) using the histogram features and calculated the modified GAP (mGAP) score by replacing DLCO with the predicted DLCO. The performances of the GAP, CT-GAP, and mGAP scores were compared using 100 repeated random-split sets.ResultsPatients with moderate-to-severe IPF had more numerous Gaussian curvatures at the fibrosis boundary, lower uniformity, and lower 10th to 30th percentiles of Gaussian curvature than controls or patients with mild IPF (all p < 0.0033). The 20th percentile was most significantly correlated with the GAP score (r = - 0.357; p < 0.001) and the CT fibrosis score (r = - 0.343; p = 0.001). More numerous Gaussian curvatures, higher entropy, lower uniformity, and 10th to 30th percentiles (p < 0.001-0.041) were associated with mortality. The mGAP score was comparable to the GAP and CT-GAP scores for survival prediction (mean C-indices, 0.76 vs. 0.79 vs. 0.77, respectively).ConclusionsGaussian curvatures of fibrosis boundaries became more heterogeneous as the disease progressed, and heterogeneity was negatively associated with survival in IPF.Key points• Gaussian curvature of the fibrotic lung boundary was more heterogeneous in patients with moderate-to-severe IPF than those with mild IPF or normal controls. • The 20th percentile of the Gaussian curvature of the fibrosis boundary was linearly correlated with the GAP score and the CT fibrosis score. • A modified GAP score that replaced the diffusing capacity of carbon monoxide with a composite measure using histogram features of the Gaussian curvature of the fibrosis boundary showed a comparable ability to predict survival to both the GAP and the CT-GAP score.

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Dataset Information

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study.

Background and objective

Methods

Results

Conclusion

Publications

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study.

Similar Datasets

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