Importance of the reversed halo sign for the diagnosis of angioinvasive pulmonary aspergillosis.

We are very grateful for the interest Marchiori et al. have shown in our recently submitted article, Airway and parenchymal manifestations of pulmonary aspergillosis [1]. We also read with interest their fascinating study highlighting morphologic features of the reverse halo sign, which in the correct clinical context, may alert the radiologist to the presence of a possible invasive fungal infection [2]. Although the reverse halo sign is a nonspecific CT sign, seen in a variety of different disease entities [3], the work of Marchiori et al. clearly demonstrates that in immunocompromised patients, this broad differential diagnosis can be distilled to the correct diagnosis and impact management decisions and outcome. These observations are clearly of great help to more general thoracic radiologists working outside transplant centres, who may have less experience