Advances in radiologic assessment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is defined as a chronic obstru ctive disorder of the airways resulting from a combination of emphysema and a reduction in the caliber of the airways.(54) Although COPD is defined in functional terms, chest radiography and CT scans assess primarily lung mor phology. It therefore is necessary to consider separately the role of imagi ng in the various entities that may cause airways obstruction in smokers. C T, particularly high-resolution CT (HRCT), defined as thin-section CT (sect ions 1-2 mm in thickness) optimized by using an edge-enhancing reconstructi on algorithm, is ideally suited to detect and assess the morphologic change s seen in these conditions. This review summarizes the current role of the chest radiograph and CT scan in the assessment of emphysema, chronic bronchitis, and respiratory bronch iolitis.