A Computer-based Analysis for Identification and Quantification of Small Airway Disease in Lung Computed Tomography Images

Abstract

Computed tomography (CT) imaging is being increasingly used in clinical practice for detailed characterization of lung diseases. Respiratory diseases involve various components of the lung, including the small airways. Evaluation of small airway disease on CT images is challenging as the airways cannot be visualized directly by a CT scanner. Small airway disease can manifest as pulmonary air trapping (AT). Although AT may be sometimes seen as mosaic attenuation on expiratory CT images, it is difficult to identify diffuse AT visually. Computer technology advances over the past decades have provided methods for objective quantification of small airway disease on CT images. Quantitative CT (QCT) methods are being rapidly developed to quantify underlying lung diseases with greater precision than subjective visual assessment of CT images. A growing body of evidence suggests that QCT methods can be practical tools in the clinical setting to identify and quantify abnormal regions of the lung accurately and reproducibly. This review aimed to describe the available methods for the identification and quantification of small airway disease on CT images and to discuss the challenges of implementing QCT metrics in clinical care for patients with small airway disease.

Computer-assisted evaluation of small airway disease in CT scans of Iran-Iraq war victims of chemical warfare by a locally developed software: comparison between different quantitative methods

“…Expiratory CT air trapping (AT) is regarded as specific for SAD. The AT regions are visible on expiratory phase CT as well-defined low attenuated geographic regions with contours that follow the frameworks of the affected secondary pulmonary lobules [ 9 – 11 ]. Visual assessment of AT is subject to the limitations inherent to intra-rater subjectivity and reliability.…”

“…Numerous studies have evaluated the ability of different QCT methods to identify functional SAD in chronic obstructive pulmonary disease (COPD). The ability of QCT methods to identify SAD has been demonstrated in previous studies on COPD patients [ 11 ]. However, to the best of our knowledge, no study has evaluated the application of QCT methods in patients with a history of chemical warfare exposure.…”