Left Upper Lobe Consolidation

Introduction

The Left Upper Lobe (LUL) is a relatively uncommon site for consolidation. The diagnosis of a subtle LUL consolidation can be very tricky on the PA/AP view image and can be relatively easy on the lateral image.

The Meaning of the Term Consolidation

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 meanings 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X-ray examination and notes the presence of consolidation he/she is simply stating that some of the long airspace has been replaced by a fluid.

Notes on Consolidation

• 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

The Left Upper Lobe (LUL) Anatomy

adapted from <a class="external" href="http://books.google.com.au/books?id=Bif0zpmEWtAC" rel="nofollow" target="_blank">By Fred W. Wright Radiology of the Chest and Related Conditions: Together with an Extensive Illustrative Collection of Radiographs CRC Press, 2002</a>

On the left there is no middle lobe; the anatomical equivalent region corresponding to the right middle lobe is known as the lingula, and like the RML, is also composed of two segments. Unlike their counterparts on the right however, the segments are stacked one on top of another, rather than side. <a class="external" href="http://lib.cpums.edu.cn/jiepou/tupu/atlas/www.vh.org/adult/provider/radiology/LungAnatomy/RightLung/RtLungSegAnat.html" rel="nofollow" target="_blank">http://lib.cpums.edu.cn/jiepou/tupu/atlas/www.vh.org/adult/provider/radiology/LungAnatomy/RightLung/RtLungSegAnat.html</a>. Note that upper lobe pathology could appear very low on a chest X-ray image. The upper lobe is the anterior lobe as much as it is the upper lobe.

adapted from <a class="external" href="http://books.google.com.au/books?id=Bif0zpmEWtAC" rel="nofollow" target="_blank">By Fred W. Wright Radiology of the Chest and Related Conditions: Together with an Extensive Illustrative Collection of Radiographs CRC Press, 2002</a>

Plain Film Appearances of Lung Consolidation

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

•Appears as an area of increased opacity within the LUL •Characteristically not a dense opacity of the PA view •Often loss of the upper mediastinal contour	•Opacity left hemi-thorax •Air-bronchogram lines •Some loss of left heart border
•Can be sharply bordered by the oblique fissure •Does not involve the diaphragm	•Opacity seen anterior to the oblique fissure

Case 1

	There is increased abnormal opacity seen within the apex of the left lung. This is likely to represent consolidation within the LUL. Benjamin Felson (<a class="external" href="http://www.amazon.com/Chest-Roentgenology-Benjamin-Felson/dp/0721635911/ref=sr_1_2?ie=UTF8&s=books&qid=1252240078&sr=1-2" rel="nofollow" target="_blank">Chest Roentgenology, W.B. Saunders, 1973, p22</a>) notes that "A radiopacity involving the extreme apex of the lung is almost invariably situated in the apical segment of the upper lobe".
	There is consolidation within the LUL confirmed on the lateral chest image. The opacity may appear deceptively dense because of the superimposed densities.
	An apical lordotic view was performed to see if the pathology could be better demonstrated.

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