Neck Radiograph Halo Sign: Do Not Be Fooled.

An aerodigestive foreign body injury in the throat is an otorhinolaryngology (ORL) emergency. Button batteries and coins are the most common foreign body aspirations or ingestions among the paediatric population. An impacted button battery in the aerodigestive tract is a surgical emergency, requiring urgent removal to prevent complications arising from the corrosive nature of the button battery. We report two cases that were brought in with a history of foreign body ingestion. Both neck radiographs showed a double-ring opaque shadow. The first child had a button battery eroding into his oesophagus. The second case is an ideally impacted stack of coins of different sizes that mimic a double-ring shadow, better known as a halo sign, in an antero-posterior neck radiograph. These cases are unique in comparing ingested coins in alignment with a button battery and a radiological examination mimicking that of a button battery. In this report, we emphasize the importance of a thorough history, endoscopic examination, and the limitations of radiographs in the initial assessment of an ingested foreign body in terms of management and prediction of morbidity.