[Radiological diagnosis --diagnosis and evaluation by chest X ray, chest CT and chest MRI].

A plain chest X-ray is not useful for the diagnosis of early stage of COPD, but severe COPD has some characteristic radiographic signs. Because of absence of vasculature, radiolucency of lung fields is recognized. Depression and flattening of the diaphragm, tear -drop heart and increase in the retrosternal airspace are detected as signs of lung hyperinflation. High-resolution CT(HRCT) scanning is more sensitive to diagnose of COPD. COPD can be detected as low attenuation area. CT is also useful in classifying patterns of emphysema(centriacinar, panacinar and distal acinar type). Although the assessment of COPD is still limited by MRI, progress of MRI techniques in pulmonary ventilation, such as hyperpolarized noble gas MRI and oxygen enhanced MRI, enabled evaluation of COPD.