Diagnostic imaging of idiopathic adult respiratory distress syndrome (ARDS)/diffuse alveolar damage (DAD) histopathological correlation with radiological imaging

In ten patients with idiopathic adult respiratory distress syndrome (ARDS) who had histopathologically diffuse alveolar damage (DAD), and who did not have specific underlying diseases, we compared the histopathological findings with their radiographic images in order to study the detail analysis of radiographic images and the clinical courses. These patients were roughly classified as having the interstitial pneumonia dominant type (type IP) of idiopathic ARDS, in which alveolar septal thickening, alveolitis, or both were the predominant histological findings and images showed increasing attenuation of lung fields with small honeycomb lung, or the organizing pneumonia dominant type (type OP), in which organizing exudate predominantly filled the alveoli histologically and images showed consolidation shadows with some air. Hyaline membrane was seen very frequently in patients with a short clinical course, and in accordance with a longer clinical course, widespread fibrosis and honeycomb lung covered by organizing hyaline membrane was seen with both types. Patients with type OP in whom collapse of the normal pulmonary structure was less and for whom changes on radiographic images were larger seemed to respond relatively favorably to steroid treatment, as judged from pulmonary function and radiographic images.