[Diagnostic imaging--CT, dynamic CT, and others].

Technical advances have raised computed tomography(CT) as a strong diagnostic tool of clinical imaging. Emphysematous changes can be quantitatively analyzed as low attenuation area which correlated with diffusion capacity, quality of life, and nutritional states, but not so much with forced expiratory volume in one second. With co-analyzing airway wall thickness, those are possibly useful to understand phenotypes. Dynamics of airway during breathing can be visualized by dynamic CT such as electron-beam CT. Dynamic airway narrowing is a representative feature in emphysematous lung.