Imaging of pulmonary infections after lung transplantation: a pictorial essay of early and late computed tomography findings

Pulmonary infections are among the most common complications after lung transplants and a major cause of morbidity and mortality in these patients. Computed tomography is one of the main non-invasive diagnostic tools for detecting lung infections but characterizing the correct etiology may be very challenging. Indeed, although several pathogens show typical patterns at imaging, others, such as bacteria, may demonstrate quite unspecific features. Therefore, additional parameters, like the timing of the infection, should be evaluated to support the radiologists in narrowing the differential diagnoses. In fact, it has been demonstrated that several pathogens, like Candida albicans, usually occurring within the first month after the transplant, frequently occur at specific time points. Thus, aim of this review is to make radiologists and clinicians familiar with the computed tomography patterns of pulmonary infections occurring after lung transplant, considering the etiology and the time of onset, according to the extensive experience gained in our tertiary center.