Chest X-ray Systematic Approach
Describing abnormalities

Key points

  • 'Shadowing', 'opacification', 'increased density', 'increased whiteness' are all acceptable terms
  • 'Lesion descriptors' may lead you towards a diagnosis
  • Be descriptive rather than jumping to a diagnosis

'Lesion descriptors'

  • Tissue involved - Lung, heart, aorta, bone etc
  • Size - Large/Small/Varied
  • Side - Right/Left - Unilateral/Bilateral
  • Number - Single/Multiple
  • Distribution - Focal/Widespread
  • Position - Anterior/Posterior/Lung zone etc
  • Shape - Round/Crescentic/etc
  • Edge - Smooth/Irregular/Spiculated
  • Pattern - Nodular/Reticular(net-like)
  • Density - Air/Fat/Soft-tissue/Calcium/Metal

The art of radiology is not merely in spotting and describing abnormalities, it is also in knowing how to communicate the relevance of these abnormalities, and knowing what can be ignored.

At first, describing X-ray abnormalities can be difficult, and many medical students want rules of terminology. However, there really are no rules, as long as the terms used are not misleading.

The main difficulty comes in describing abnormalities of the lung parenchyma. What some may call 'shadowing,' others may call 'opacification,' 'whiteness,' or 'increased density.' In fact, all of these are acceptable terms.

Describing a chest X-ray abnormality can be likened to describing a skin rash in a dermatology patient, or a lump in a surgical patient. Attention should be given to factors such as location, size, shape and density of an abnormality. The process of description often helps with diagnosis - see the list of 'lesion descriptors.'

'Shadows, opacities, densities'

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'Shadows, opacities, densities'

  • Tissue involved - Lung
  • Size - Small (<2 cm)
  • Side - Bilateral
  • Number - Multiple
  • Distribution - Widespread
  • Position - Mainly middle to lower zones
  • Shape - Round
  • Edge - Irregular
  • Pattern - Nodular
  • Density - Soft-tissue

Diagnosis

  • Description helps with diagnosis. Once you have put all the above terms together, there can only be one diagnosis.
  • Metastatic disease

Specific findings

There are also specific findings that may point you in the direction of a diagnosis. For example, blunting of the costophrenic angles may lead you to think there are pleural effusions. Evidence of consolidation such as air bronchogram, may make you think infection is the diagnosis. These phenomena often need little in the way of description.

However, if you see one of these 'tell-tale' signs, try not to jump in with a diagnosis. Taking a moment to systematically describe the abnormality may lead you to notice that blunting of the costophrenic angles is due to lung hyperexpansion rather than an effusion, or that an area of lung consolidation has an adjacent eroded rib, making cancer more likely than infection.

'Tell-tale' pitfall

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'Tell-tale' pitfall

  • The costophrenic angles are blunt and you may incorrectly assume this is due to pleural effusions.
  • However, a systematic assessment reveals that the diaphragm lies well below the 7th rib in the mid-clavicular line (white arrow). The diaphragm should not lie below the red line.
  • There are no pleural effusions.

Diagnosis

  • Lung hyperexpansion due to emphysema

Page author: Salisbury NHS Foundation Trust UK (Read bio)

Last reviewed: September 2016