Figure 2. 17-year-old male patient with leukaemia and fever at aplasia after bone marrow transplant. (a) Axial non-enhanced CT-image shows focal subpleural consolidation in the right pulmonary lower lobe, due to lung parenchymal necrosis by invasive pulmonary aspergillosis. On unenhanced CT the central hypodense parenchymal infarction is though easily distinguishable. It is surrounded by inflammatory reaction (black arrow) and a hyperdense ring in between (white arrow), presumably caused by haemorrhage (confirmed by biopsy). (b) One of the follow-up CT examinations was performed after intravenous contrast material administration, in order to exclude other potential infectious complications in the abdomen. Easier delineation of infarcted lung parenchyma is obvious (white arrow). However, unenhanced CT is also of diagnostic quality.