isolated to the right upper lobe is mitral regurgitation. The radiographic findings may easily be
confused with pneumonia. As in the case of diffuse CHF changes, initiation of therapy should
rapidly reverse the findings, unlike in pneumonia (40).
Clinical and Radiologic Diagnosis of Cavitary Pneumonia
The term “cavity” with respect to the lung is used to describe an air-containing lesion with a
thick wall (>4 mm) or within a surrounding area of pneumonia or an associated mass.
Cavitary lung lesions result from neoplastic, autoimmune, and infectious processes. The
common bacterial pneumonias that may progress to cavitation areS. aureus,Klebsiella, and
P. aeruginosa(41).
Hospitalized, debilitated patients are most prone to the development ofS. aureus
pneumonia. Staph pneumonia is a bronchopneumonia that initially appears on chest radiographs
Figure 20 (A) Chest radiograph demonstrates dense opacification in the left upper lobe and at the right lung
base in an adult patient with multilobar pneumonia. (B) CT scan of the chest in the same patient demonstrates
consolidation in the left lower and right upper lobes containing air bronchograms, again consistent with multifocal
pneumonia. Bilateral pleural effusions are also present posteriorly.
94 Luongo et al.