Ventilation/perfusion SPECT in chronic obstructive pulmonary disease: an evaluation by reference to symptoms, spirometric lung function and emphysema, as assessed with HRCT.
PURPOSE: Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation which is not fully reversible. Despite the heterogeneity of COPD, its diagnosis and staging is currently based solely on forced expiratory volume in 1 s (FEV(1)). FEV(1) does not explain the underlying pathophysiology of airflow limitation. The relationship between FEV(1), symptoms and emphysema extent is