Feature ensemble for quantitative analysis of emphysema in CT imaging

Chronic obstructive pulmonary disease is a non-reversible disorder characterized primarily by a dominant emphysema or bronchitis. Since early treatments can help to control the symptoms, the quantification of emphysema has become an important topic. Here, we introduce a novel procedure to quantify emphysematous lesions using an ensemble of features based on log-Gabor filters, mean difference technique, and intensity values. This set captures both spatial and frequency variations and provides a suitable description of lung tissue. Leave-patient-out cross-validation was employed on the computed tomography emphysema database to validate our proposal. The sensitivity and specificity achieved were 91.22% and 95.48%, respectively. Such results have demonstrated that the proposed methodology could assist in quantification of emphysema.