Chest radiography allows detection of moderate and severe emphysema but does not allow quantitation of severity of disease or detection of mild emphysema. Chest radiography is helpful in assessing complications of emphysema such as pneumothorax or secondary infection of a bulla. HRCT provides a detailed image of emphysematous lung disease comparable to that of macroscopic pathologic appearance. The main role of HRCT in patients with COPD is in the preoperative assessment of patients being considered for bullectomy or LVRS.