right lower lobe consolidation

Right lower lobe consolidation refers to consolidation in part (incomplete) or all (complete) of the right lower lobe.

Pathology

Consolidation refers to the alveolar airspaces being filled with fluid (exudate/transudate/blood), cells (inflammatory), tissue, or other material.

The list of causes of consolidation is broad and includes:

• pneumonia
• adult respiratory distress syndrome (ARDS)
• interstitial pneumonias
• pneumonitis
• sarcoidosis

Radiographic features

Consolidation is usually obvious on CT with the anatomical location easy to define through visualization of the pleural fissures, however features can be subtle on chest radiography.

Plain radiograph

Features of right lower lobe consolidation on CXR include:

• opacification of the right lower zone, that may abut the oblique fissure
• obscuration of the right hemidiaphragm (silhouette sign)
• normal (clear and distinct) right heart border (c.f. middle lobe consolidation)
• normal (clear and distinct) right superior mediastinal contour (c.f. right upper lobe consolidation)
• obscuration of the right hilum, particularly the inferior hilum
• visible horizontal fissure
• air bronchograms
• on lateral CXR: triangular opacification posterior and inferior to right oblique fissure with obscuration of the dome and posterior aspect of the right hemidiaphragm

General considerations

It must be remembered that the homogeneity of the consolidation will be influenced by any underlying lung disease.

Occasionally with complete lobar consolidation, there may be an increased volume of the affected lobe, rather than the more frequent collapse. When the fissures are outwardly convex, the appearance is referred to as the bulging fissure sign.

A mnemonic to remember the general features of consolidation is A2BC3.

Differential diagnosis

• right lower lobe collapse will show signs of volume loss

Siehe auch:

• Atelektase
• right middle lobe consolidation

und weiter:

• Konsolidierung der Lunge