Morphological basis of radiological band shadows on chest radiographs

Lungs of unselected cadavers were fixed at necropsy using a formalin vapour technique. "Band shadows" were identified in the excised lungs and these were correlated with in vivo radiographs and with the morphological changes in the lung. Persistent shadows were produced by pulmonary infarction, subsegmental atelectasis, and septal fibrosis singly and in combination. Potentially transient shadows were seen in association with atelectasis and pulmonary oedema.