Airflow Limitation and Airway Dimensions in Chronic Obstructive Pulmonary Disease

Abstract

Rationale: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation caused by emphysema and/or airway narrowing. Computed tomography has been widely used to assess emphysema severity, but less attention has been paid to the assessment of airway disease using computed tomography. Conclusions:We are the first to use three-dimensional computed tomography to demonstrate that airflow limitation in COPD is more closely related to the dimensions of the distal (small) airways than proximal (large) airways.

Dissimilarity-Based Classification of Anatomical Tree Structures

“…where M * is obtained via (1). Segmented anatomical trees are likely to contain differing number of branches, i.e., |X 1 | = |X 2 |, and the above formulation does not account for this.…”

“…WA% is computed from the segmented airway tree (lumen and outer wall). This is the most commonly used measure of airway disease in CT [1][2][3]18]. It is also used in asthma [4].…”

“…Examples of such structures and applications are: quantification of airway tree abnormalities in, e.g., chronic obstructive pulmonary disease (COPD) [1][2][3] or asthma [4], quantification of arterial stenosis in the circle of Willis in the brain [5], and quantification of retinopathy of prematurity in retinal vessels [6]. The goal is to relate the global state of the anatomical tree to the disease status based on local information in the branches of the tree.…”

“…The goal is to relate the global state of the anatomical tree to the disease status based on local information in the branches of the tree. This goal is often achieved by considering only parts of the tree and computing an average feature across the branches in those parts [1][2][3][4][5][6].…”

“…The value used CT-based marker of airway disease in the clinical literature that, despite its simplicity, have shown a significant correlation with PFTs [1][2][3].…”