ICU Chest Films > Lung Processes > Pneumonia in the ICU > Radiographic Appearance

Radiographic Appearance of Pneumonia

The radiographic appearance of pneumonia may be difficult to differentiate from atelectasis or early ARDS. Classically, pneumonia first appears as patchy opacifications or ill-defined nodules. It is often multifocal and bilateral, occurring most often in the gravity dependent areas of the lung. This feature makes it difficult to distinguish from atelectasis or pulmonary edema. E-coli and pseudomonas species can rapidly involve the entire lung. Their symmetric pattern often simulates pulmonary edema. The presence of patchy air space opacities, air bronchograms, ill-defined segmental consolidation or associated pleural effusion support the diagnosis of pneumonia. Occassionally, in gram-negative pneumonias small luciencies may be found within consolidated lung which may represent unaffected acini or areas of air trapping. This is particularly likely to occur in patients with underlying COPD. However, these must be distinguished from lucencies created by cavitation and abscess formation.

Complications of nosocomial pneumonias can have severe consequences and require immediate attention. Unlike community acquired pneumonia, pleural effusions caused by gram-negative organisms are more likely to represent empyema and therefore require drainage. Other complications of nosocomial pneumonias include lung abscess formation and bronchopleural fistulas.

A patchy infiltrate obscurring the right heart border is a common radiographic presentation of right middle lobe pneumonia (left). Following treatment with intervenous antibiotics the pneumonia resolved (right).