Invasive pulmonary aspergillosis (IPA) is an opportunistic infection that primarily affects recipients of solid organ transplants (SOTs) and patients with chemotherapy- induced neutropenia.Although both of these populations are at high risk for IPA, they differ with regards to the specific defects in host defense mechanisms that increase their risk for IPA. Chemotherapy- induced neutropenia is the principal defect affecting patients with hematologic malignancies, whereas transplant recipients tend to have dysfunctional T cells and phagocytes, as a result of immunosuppressive drug therapy. Thus, the patterns of IPA-related infection and inflammation may differ according to the type of underlying immune defect. Although the clinical and radiological features of IPA in patients with neutropenia have been extensively studied, little is known about the characteristics of IPA in SOT recipients. The investigators therefore compared the IPA- related clinical and radiological findings in SOT recipients with those of neutropenic patients.