History 3-year-old boy brought to the emergency department 2 hours after a suspected swallowed object. Drooling and refusing to eat; no respiratory distress.
Frontal and lateral chest radiographs · Click an image to enlarge.
Answer each question aloud before you reveal it. Marks and domains appear only in the revealed answers, as in the exam.
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Q1 Describe the findings and their location on the frontal and lateral views.
Reveal answer
A Annotated B Annotated 2 marks Observation
- Frontal: round, well-defined metallic density seen face-on at the thoracic inlet / upper oesophagus (about the level of the clavicles) (1)
- Lateral: seen edge-on as a linear density behind the trachea, i.e. in the oesophagus (1)
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Q2 What is your preferred diagnosis, and what is the single most important differential? How do you tell them apart?
Reveal answer
3 marks Interpretation
- Preferred: coin impacted in the upper oesophagus (thoracic inlet / cricopharyngeal level, the commonest site) (1)
- Differential: button (disc) battery (1)
- Battery: double-ring / halo on the frontal view and a step-off at the edge on the lateral; a coin is uniform with no halo (1)
Examiner note Always zoom on the edge: the halo can be subtle on small batteries.
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Q3 How should this child be managed?
Reveal answer
2 marks Management/Safety
- Symptomatic oesophageal coin (drooling, cannot manage secretions): urgent endoscopic removal; an asymptomatic coin may be observed for up to 24 h (NASPGHAN) (1)
- Repeat the radiograph just before endoscopy (the coin may have passed); if a battery cannot be excluded, treat it as an emergency: removal ideally within 2 hours (ESPGHAN 2021) (1)
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Q4 Why is this object seen face-on on the frontal view?
Reveal answer
1 mark Applied sciences
- The oesophagus is a collapsible tube that is widest in the coronal plane, so flat objects usually lie coronally; the trachea (C-shaped rings, posterior membrane) tends to hold objects sagittally (1)
Examiner note A useful rule, not an absolute one: always confirm with the lateral.
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Q5 The parent asks whether the x-rays were harmful and whether this could have been prevented. How do you respond?
Reveal answer
2 marks Intrinsic roles
- Plain language: the dose from a chest x-ray is very small, similar to a few days of natural background radiation in Australia; the films were needed and justified (1)
- Health advocacy: keep coins, magnets and button batteries out of reach; Australia has mandatory safety and information standards for button/coin batteries (ACCC, in force since 2022) (1)
Examiner note Intrinsic roles: Communicator, Health Advocate (LO §1).
End of the OSCER block (10 marks).
Beyond the exam: teaching extension
Q6–Q10: not part of the 10-mark OSCER block. Untimed, viva-style discussion: mimics and pitfalls, complications, guidelines and report wording.
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Q6 Where do swallowed objects lodge in the oesophagus?
Reveal answer
- Cricopharyngeus / thoracic inlet (the commonest site in children)
- Level of the aortic arch and left main bronchus (mid-oesophagus)
- Gastro-oesophageal junction; also at any stricture (e.g. repaired oesophageal atresia)
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Q7 How do button batteries injure the oesophagus, and what are the complications?
Reveal answer
- Current through the mucosa generates hydroxide at the negative pole, causing liquefactive necrosis; serious injury can occur within 2 hours (Litovitz 2010)
- Orientation matters: the narrower negative side causes the worst injury
- Complications: perforation, mediastinitis, tracheo-oesophageal fistula, aorto-oesophageal fistula (catastrophic haemorrhage), stricture, vocal cord palsy
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Q8 Which other ingested objects need urgent action?
Reveal answer
- Multiple magnets (or a magnet plus metal): pressure necrosis of the bowel wall, fistula, perforation
- Sharp or long objects; food bolus with complete obstruction
- Radiolucent objects: if symptoms persist with a normal film, discuss endoscopy or a contrast study
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Q9 How do you keep the paediatric dose low here?
Reveal answer
- Justify every exposure: a frontal film covering the neck, chest and abdomen finds most objects; add a lateral when one is seen
- Collimate, use paediatric exposure settings, and avoid repeat films unless they change management (the pre-endoscopy check does)
- Radiation protection and patient safety: LO §2.3; advocate for the lowest-dose pathway (LO 6.1.8)
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Q10 Draft the key sentences of your report.
Reveal answer
- 'Round radiopaque object at the thoracic inlet, face-on on the frontal view and edge-on behind the trachea on the lateral, consistent with an oesophageal coin. No halo or step-off to suggest a button battery.'
- 'Discussed with the ED / paediatric surgical team at [time].'
End of questions. Reveal the diagnosis, key takeaways and syllabus mapping below.
Reveal diagnosis, key takeaways & syllabus mapping
Diagnosis Oesophageal coin (exclude button battery)
Key takeaways
- A round metallic density in a child is a button battery until the edge proves otherwise.
- Face-on on the AP plus edge-on behind the trachea = oesophagus.
- Symptomatic coin: urgent endoscopy. Battery: emergency, ideally within 2 hours.
- Re-image just before endoscopy, and keep the dose low.
Syllabus mapping
| OSCER station | Paediatrics |
|---|---|
| Learning Outcomes section | §6.10 Paediatric (conditions listed in Appendix 1 E and F) |
| Appendix 1 condition | Swallowed foreign bodies (Appendix 1 F, Oesophagus, p73); Inhaled and swallowed foreign bodies (Appendix 1 E, Cardiothoracic, Traumatic conditions, p69) |
| Category | Category 1 |
| Key Condition | Yes |
| Core marks by domain | Observation 2 · Interpretation 3 · Management/Safety 2 · Applied sciences 1 · Intrinsic roles 2 (= 10) |
| Learning objectives | Localise an ingested object using two views; Exclude a button battery and know how urgent it is; Explain radiation risk and prevention to a parent |
Mapped to the RANZCR Clinical Radiology Learning Outcomes v1.3 (January 2024), section 6 and Appendix 1.
Further reading
- Litovitz T, Whitaker N, Clark L, et al. Emerging battery-ingestion hazard: clinical implications. Pediatrics. 2010;125(6):1168–1177. PMID 20498173.
- Kramer RE, Lerner DG, Lin T, et al. Management of ingested foreign bodies in children: a clinical report of the NASPGHAN Endoscopy Committee. J Pediatr Gastroenterol Nutr. 2015;60(4):562–574. PMID 25611037.
- Mubarak A, Benninga MA, Broekaert I, et al. Diagnosis, management, and prevention of button battery ingestion in childhood: a European Society for Paediatric Gastroenterology Hepatology and Nutrition position paper. J Pediatr Gastroenterol Nutr. 2021;73(1):129–136. PMID 33555169.
- RANZCR. Clinical Radiology Learning Outcomes, v1.3 (January 2024), §6 and Appendix 1. Sydney: RANZCR.
- RANZCR. Clinical Radiology Phase 2 OSCER Sample Questions, v1.6 (4 May 2026). Sydney: RANZCR. (Format reference only; no RANZCR images reproduced.)
Always check current Australian/local guidelines.
Image credits
- A by James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons. Changes: resized and re-encoded (WebP/JPEG). Teaching arrows and labels are a separate overlay added by this site. Adapted image shared under the same licence.
- B by James Heilman, MD, CC BY-SA 3.0, via Wikimedia Commons. Changes: resized and re-encoded (WebP/JPEG). Teaching arrows and labels are a separate overlay added by this site. Adapted image shared under the same licence.
Original file titles are listed on the image credits page (they may reveal the diagnosis).