Radiology – Integrated Training Initiative (R-ITI) | Paediatrics | Multiple Lung Opacities

Multiple lung opacities
Session overview
Description
This session reviews the approach to (and appearances of) multiple pulmonary nodules in children.

Learning objectives
By the end of this session you will be able to:

• Recognise the imaging appearances and differentiate between the causes of multiple pulmonary opacities
• Provide a reasonable differential diagnosis
• Advise any further imaging that may be useful

Prerequisites
Before attempting this session you should have knowledge of:

• Anatomy of the chest on radiographs and computed tomography (CT)

Multiple pulmonary opacities are quite uncommon in paediatric practice. They are less prevalent than solitary pulmonary opacities in children, and are much rarer than in adults.

Pulmonary opacities are usually rounded and nodular and are identified because of their size, density or both. In the context of multiple lesions, any individual opacity can look identical to a solitary lesion, but analysis of their appearance and the clinical features can help narrow the differential diagnosis.

Key anatomy
The lung markings visible on chest radiographs (CXRs) are predominantly vascular-pulmonary arteries and veins seen end-on and en-face. There is some contribution from bronchial walls and interstitium but this is minimal. Pulmonary vessels taper and their cross-sectional diameter decreases toward the lung periphery.