Radiology – Integrated Training Initiative (R-ITI) | Paediatrics | Ring Shadows

Ring Shadows
Session Overview
Description
This session is designed to illustrate the appearance on imaging of the various types of ring shadows and correlate the appearance with the clinical presentation.

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

• Recognise patterns of ring shadows
• Identify the causes of ring shadows
• Correlate clinical presentation with the imaging findings

Ring shadows visible on the chest radiograph (CXR) represent air-filled cystic lesions in the chest and correspond to collections of air surrounded by a visible wall of varying thickness. The differential diagnosis of ring shadows in the chest in children can be divided into two groups: congenital and acquired lesions.

Congenital lesions include:

• Cystic adenomatoid malformation
• Diaphragmatic hernia
• Congenital lung cyst
• Congenital lobar overinflation (CLO) (also previously knows as congenital lobar emphysema)

Acquired lesions include:

• Inflammatory pneumatocoeles
• Bronchiectasis
• Cavitating pneumonia
• Pseudocysts due to barotrauma as in bronchopulmonary dysplasia
• Traumatic diaphragmatic hernia
• Hiatal hernia
• Pulmonary interstitial emphysema

The clinical findings are vital in making a diagnosis as it can be difficult to differentiate between the different types of ring shadows from the imaging findings alone.