This is the answer page to Case 6 from the page titled What is the Value of the Lateral Chest Projection?

• What is the Value of the Lateral Chest Projection?

• Patterns of Consolidation

• Patterns of Consolidation- LUL

• Lung Anatomy

This 24 year old male presented to the Emergency Department with "cough, fever, crepetation LL zone" The patient was referred for chest radiography This is a PA erect chest projection image taken with CR system

There is a suggestion of thick walled bronchii and airbronchogram lines within the LLL behind the heart shadow (arrowed) This is undeniably subtle but correlates well with the patient's clinical presentation A lateral projection image may provide additional diagnostic confidence

Lateral Projection

There is prominence of the posterior basal retrocardiac lung markings

The lung markings arrowed are prominent. The thoracic vertebral bodies should appear to darken evenly as from top to bottom. In this patient they appear to become lighter near the hemidiaphragm The appearances may reflect early pneumonitis

This patient's PA chest findings were subtle (although they were noted by the radiographer). The lateral chest projection image provided additional confidence to the diagnosis and may have been influential in treatment decisions. It is at least possible (if not likely) that this finding would have been missed in an after-hours situation where no radiologist was present. I would also suggest that the risk of misdiagnosis would be higher if a lateral projection image was not provided.