Imaging of complications of lung transplantation

With the increasing number and improved survival of lung transplant recipients, radiologists should be aware of the imaging features of lung transplants and the associated complications. Reimplantation response, a noncardiogenic pulmonary edema seen 48 hours after transplantation that subsequently resolves, varies in appearance from a mild perihilar haze to a dense consolidation in the perihilar areas and lung bases. A late complication of omentopexy (used to prevent bronchial dehiscence) is herniation of abdominal contents through the diaphragmatic incision into the thorax. Extrabronchial air collections are a radiologic manifestation of anastomotic dehiscence. Stricture formation that compromises the bronchial lumina is usually visible with plain radiography, but computed tomography can aid in the evaluation. Acute rejection is evident radiographically as new or increasing pleural effusions, septal lines, subpleural edema, peribronchial cuffing, and air-space disease, without increase in cardiac size. Radiographic features of chronic rejection include both increased and diminished lung volumes, central and peripheral bronchiectasis, localized air-space disease, partial lobar atelectasis, thin linear irregular areas of increased opacity, pleural thickening, and diminished peripheral lung markings. Infection is frequently seen, especially gram-negative pneumonias, with fewer occurrences of cytomegalovirus infection, candidiasis, and invasive aspergillosis.