Right upper lobe consolidation
Right upper lobe consolidation refers to consolidation in part (incomplete) or all (complete) of the right upper 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
- pulmonary edema due to preferential edema from a regurgitant jet of blood through the right superior pulmonary vein (secondary to a ruptured papillary muscle or mitral valve prolapse causing acute myocardial infarction)
- 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 upper lobe consolidation on CXR include:
- opacification of the right upper zone and/or apex, that may abut and outline the superior margin of the horizontal fissure
- bulging fissure sign: classically described in Klebsiella pneumonia
- obscuration of the right superior mediastinal contour (silhouette sign), such as the SVC, right paratracheal stripe and azygos arch
- obscuration of the right hilum, particularly the superior hilum
- normal (clear and distinct) right heart border (c.f. middle lobe consolidation)
- normal (clear and distinct) right hemidiaphragm contour (c.f. right lower lobe consolidation)
- air bronchograms
- on lateral CXR: triangular opacification superior and anterior to the right oblique fissure posteriorly and the horizontal fissure anteriorly
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 upper lobe collapse will show signs of volume loss
