[Imaging diagnosis of diffuse infiltrative lung diseases--the role of conventional chest X-ray]

The conventional chest X-ray is still useful tool for the diagnosis and evaluation of the diffuse infiltrative lung diseases. The basic approach to the diagnosis by chest X-ray includes the pattern recognition of the abnormal shadows in the lungs, the predominant distribution of them and the presence of volume loss or of overinflation in addition. Typical cases of the idiopathic interstitial pneumonia show diffuse small nodules or ground glass densities in the beginning and proceed to reticulonodular shadows, and further to the coarse reticular shadows or honeycombing. These changes have the preponderance of lower lobe distribution as well as outer zone distribution. Bullous formation is also frequent findings. The characteristic findings of diffuse panbronchiolitis are diffuse small nodular shadows, overinflation and tram-lines. Middle lobe atelectasis is also associated in considerable number.