Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition with variable clinical and pathophysiologic features. Functional information of the lungs is important to understand the complex pathophysiology of COPD. With recent technical advances in the CT imaging and magnetic resonance imaging (MRI), various imaging techniques have been used for the evaluation of functional changes in COPD. The quantitative CT imaging can be used to objectively assess the severity of emphysema, airway wall changes, air trapping, and other comorbidities, which are correlated with functional aspect of COPD. The dual-energy CT imaging and functional MRI can directly assess and visualize the functional changes such as ventilation, perfusion, and ventilation–perfusion relationship with anatomically matched structural information of the lung in COPD. In this chapter, we will review the current technical status of functional imaging briefly, and focus on its clinical applications, limitations, and some of the most recent works in COPD. more...