Radiological aspects of diffuse alveolar haemorrhage

Purpose. This paper describes chest X-ray (CXR) and computed tomography (CT) findings of diffuse alveolar haemorrhage (DAH). Materials and methods. We retrospectively reviewed 23 episodes of DAH in 20 patients, 17 of known aetiology and three of unknown aetiology. All cases were studied by CXR and 15 also by CT. Parenchymal consolidations and ground-glass opacities were evaluated after dividing each lung into three regions (upper, middle, lower) for a total of six zones. Results. Consolidations or ground-glass opacities were identified on CXR in 16/20 patients, mainly in the middle fields (73%). In 4/20 patients, all with Wegener's granulomatosis, CXR was negative or demonstrated only nodular opacities; in two of these cases, CT revealed ground-glass opacities. A complete follow-up was available for ten patients: initially, they showed consolidation opacities in 36/60 zones, which persisted in 16/60 after 7 days and in 11/60 after 15 days. Conversely, ground-glass opacities increased after 7 days owing to the partial regression of consolidation opacities, and they markedly diminished after 15 days. Conclusions. DAH is radiologically characterised by a nonspecific alveolar-filling pattern. Diagnosis or suspicion of DAH needs to be supported by the evidence of haemoptysis and/or rapid-onset anaemia. CT is superior in detecting ground-glass opacities and is required in cases of suspected DAH with normal CXR findings.