Infection of the air spaces (air bronchograms) and/or interstitium of the lung.

Findings:

• Depending upon the amount and distribution of the airspaces involved, this may present as confluent parenchymal (lobar or segmental) opacity or merely patchy opacity.
• If the Interstitium is predominantly involved, it may appear as a reticulonodular pattern.
• Air bronchograms would confirm an alveolar process.
• The lung volume should not be lost (may even be increased).
• Usually all radiographic abnormalities should disappear after 6 weeks of appropriate antibiotic therapy. However, pneumonia may be complicated by abscess or empyema formation.

Examples of Pneumonias and how to determine location. (look for the silhouette sign…loss of usual visualized borders.)

Consolidation Pattern

Round Pneumonia

Round Pneumonias are found typically in the child. Most often the organism is pneumococcus. The pneumonia appears round because of poorly developed collateral pathways (pores of Kohn and channels of Lambert). Over time though initially round, it develops into a more consolidative pattern.

 

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This section written by:

LCDR Ron Boucher, MC, USN
LT Hugh McSwain, MC, USN

With some assistance from:

CDR Michael Puckett, MC, USN
ENS Robert Post, MC, USNR

Source: Operational Medicine 2001, Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300