Right upper lobe (RUL) consolidation is a relatively straightforward diagnosis. The RUL is not hidden behind the heart or diaphragm and is relatively uncomplicated except perhaps by the presence of an azygous lobe (normal anatomical variant).

One of the unfortunate aspects of the term consolidation is that its meaning can be different depending on who is using the term. When a clinician uses the term consolidation he/she is usually referring to a consolidation associated with acute pneumonia. Thus, the term consolidation and pneumonia have very similar meaning and are almost used interchangeably. Strictly speaking, the term consolidation does not imply any particular aetiology or pathology. Acute pneumonia is the commonest cause but not the only cause of consolidation. ( other causes include chronic pneumonia, pulmonary oedema and neoplasm). Thus when a radiologist has reported a chest X-ray examination and notes the presence of consolidation he/she is simply stating that some of the lung airspace has been replaced by a fluid.

• Refers to fluid in the airspaces of the lung

• Consolidation may be complete or incomplete

• The distribution of the consolidation can vary widely. A consolidation could be described as “patchy”, “homogenous”, or generalised”.

• A consolidation may be described as focal or by the lobe or segment of lobe affected

It is sometimes useful to perform an apical lordotic view to help demonstrate equivocal pathological appearances in the upper lobes. It is also advantageous to direct patients to cross their arms across their heads for the lateral view (as opposed to hands on head and elbows forward). The upper lobes are frequently partially obscured by upper arm soft tissues on the lateral view when the hands on head, elbows forward technique is used.

adapted from By Fred W. Wright Radiology of the Chest and Related Conditions: Together with an Extensive Illustrative Collection of Radiographs CRC Press, 2002	The RUL is comprised of three segments: apical, posterior, and anterior Further information on lung anatomy here Benjamin Felson (Chest Roentgenology, W.B. Saunders, 1973, p22) notes that "A radiopacity involving the extreme apex of the lung is almost invariably situated in the apical segment of the upper lobe".
adapted from By Fred W. Wright Radiology of the Chest and Related Conditions: Together with an Extensive Illustrative Collection of Radiographs CRC Press, 2002

Radiological appearances common to all lobes are:

1.Abnormal lung opacity

2.Increase in the size and number of lung markings

3.Loss of clarity of the diaphragm on the AP and/or lateral views

4.Loss of clarity of the heart border on the AP and/or lateral views

5.Air bronchogram lines

6.Loss of the normal darkening inferiorly of the thoracic vertebral bodies on the lateral view

7.Opacification of the lung behind the heart shadow or below the diaphragms

RUL consolidation will be seen as an increased opacity within the shaded area. Opacity may be sharply bordered by the horizontal fissure Some loss of outline of the upper right heart border may be apparent	Dense opacity seen above the horizontal fissure. Air-bronchogram line The lower border of the consolidation is sharply delinated by the horizontal fissure suggesting it lies in the anterior segment of the RUL
In the lateral view, there will be increased density in the RUL which may be sharply bordered by the horizontal and/or oblique fissure(s).	Dense opacity in the RUL sharply bordered by the horizontal and oblique fissures suggesting involvement of the anterior and posterior segments of the RUL

The left image is taken with the patient's arms forward resulting in the soft tissues of the upper arm overlying the upper lobes. This is not helping in the demonstration of the patient's upper lobe consolidation. The right lateral chest image is taken with the patent's arms crossed across her head and demonstrates the RUL consolidation without the confusing arm soft tissue anatomy overlying the upper lobes. It is noteworthy that the arms forward position is the safer position and should be employed in elderly patients where appropiate.

There is abnormal opacity within the RUL abutting the horizontal fissure. The horizontal fissure is slightly bowed and elevated suggesting minor collapse of the RUL associated with the consolidation	The consolidation is likely to be within the anterior segment of the RUL. The arms forward technique has resulted in superimposed soft tissue from both arms largely obscuring the area of interest.

The arrowed structure should not be mistaken for RUL pathology. This is the thymus in a child.