Imaging phenotypes of chronic obstructive pulmonary disease based on biphasic quantitative CT features

Abstract

Quantitative analysis was performed on the biphasic CT of 40 patients [43-80 (66.1±9.0) years old, including 37 males] with stable chronic obstructive pulmonary disease (COPD) to measure the percentage of emphysema (Emph%); the percentage of small airway disease (SAD%) and the square root of the wall area of hypothetical airway with internal perimeter of 10 mm (Pi10). Based on the cluster analysis of Emph%, SAD% and Pi10, the patients were divided into five imaging phenotypes including no obvious imaging abnormality type (n=11), small airway disease-dominant type (n=9), bronchial wall thickening-dominant type (n=8), emphysema-dominant type (n=6) and mixed type (n=6). Patients with the same Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade had similar degree of airflow limitation, but the lesion components were not identical. Being different from the traditional imaging classification, even in the cases of mild emphysema, they can be further divided into small airway disease-dominant type and bronchial wall thickening-dominant type according to the difference of airway disease.