When is a neck radiograph indicated for a suspected foreign body in the airway or esophagus?

Neck Radiography for Suspected Foreign Body

Neck radiographs (including lateral views) are indicated as initial screening for suspected esophageal or airway foreign bodies, particularly for radiopaque objects, though they have significant limitations with false-negative rates up to 47% for esophageal foreign bodies and should not delay definitive management when clinical suspicion is high. 1

When to Order Neck X-rays

Initial Screening Indications

• Obtain neck, chest, and abdominal radiographs (Grade 1C) to assess presence, location, shape, and size of radiopaque or unknown shape objects 1
• Biplanar radiography (AP and lateral views using soft-tissue technique) is recommended to reduce false-negative rates and differentiate between tracheobronchial versus esophageal foreign bodies 1
• Lateral neck radiographs achieve detection rates of 70-80% for foreign bodies in the hypopharynx and upper cervical esophagus 2

Specific Clinical Scenarios

For Esophageal Foreign Bodies:

• Most useful when foreign bodies are lodged in the hypopharynx or cervical esophagus (detection rate 72.5%) 3
• Poor detection in oropharynx (0% detection rate) 3
• Should be obtained after negative oral examination and fiberoptic laryngoscopy 3

For Airway Foreign Bodies:

• Neck radiography may be obtained in suspected upper airway obstruction due to infections or foreign bodies 4
• However, in pediatric airway foreign bodies, radiographic imaging should not alter the decision for surgical intervention when history and physical examination are suspicious 5

Critical Limitations to Understand

High False-Negative Rates

• Overall false-negative rate up to 47% for plain radiography 1
• Extremely high false-negative rates (up to 85%) for:
  • Food bolus impaction 1
  • Thin metal objects 1
  • Wood and plastic objects 1
  • Glass fragments 1
  • Fish or chicken bones 1

Radiographic Findings and Their Accuracy

• Presence of radiopaque density: 84.3% accuracy 6
• Abnormal air column lucency: 66.8% accuracy 6
• Combined radiopaque density + air column lucency: 90.6% accuracy (highest practical value) 6
• Loss of cervical lordosis: 54.0% accuracy (poor single diagnostic sign) 6
• Increased prevertebral soft-tissue thickness: 60.9% accuracy; be alert when >20mm at C6 6

When CT is Required Instead

Proceed directly to CT scan (Grade 1B) in these situations: 1

• Suspected perforation or complications (abscess, mediastinitis, aortic/tracheal fistulas)
• Negative plain radiographs but persistent symptoms, especially with suspected bone fragments
• CT sensitivity is 90-100% vs. plain X-ray sensitivity of 32% for fish bone impaction 1

Common Pitfalls to Avoid

• Do not let negative radiographs delay endoscopy when clinical suspicion is high - 80-90% of ingested foreign bodies pass spontaneously, but persistent symptoms warrant endoscopic evaluation even with negative imaging 1
• Avoid contrast swallow studies (Grade 1B) - they increase aspiration risk with complete obstruction and impair endoscopic visualization 1
• Recognize interpretation challenges: Multiple overlapping soft-tissue structures and variable laryngeal cartilage calcification patterns in adults make lateral neck radiographs difficult to interpret 2
• Junior doctors miss 66.6-79.2% of positive findings on lateral neck radiographs, highlighting the need for careful review 7

Clinical Algorithm

1. History and physical examination for dysphagia, odynophagia, drooling, stridor, or respiratory distress 1
2. Oral examination and fiberoptic laryngoscopy first for oropharyngeal assessment 3
3. Obtain biplanar neck/chest/abdominal radiographs if foreign body has passed beyond oropharynx 1
4. If radiographs positive: Proceed to appropriate endoscopy based on urgency
5. If radiographs negative but symptoms persist: Proceed to CT scan or endoscopy based on clinical suspicion 1
6. Never delay definitive management for imaging when high-risk foreign bodies (sharp objects, batteries, magnets, complete obstruction) are suspected 1