What x-ray view, Anteroposterior (AP) or Posteroanterior (PA), is needed to look for a swallowed bone?

X-Ray View for Swallowed Bone Detection

For a swallowed bone, obtain a PA (posteroanterior) chest X-ray with lateral view as the initial imaging study, but recognize that plain radiography has a false-negative rate up to 85% for fish and chicken bones, making CT scan essential when clinical suspicion remains high despite negative X-rays. 1, 2

Initial Imaging Approach

Standard Radiographic Views

• PA and lateral chest radiographs are the recommended initial imaging for suspected esophageal foreign bodies, as they provide significantly better sensitivity than single AP views 3
• PA chest radiographs combined with lateral views achieve 83.9% sensitivity for detecting foreign bodies in the chest/esophagus, compared to only 67.3% for AP radiographs alone 3
• The PA view is preferred over AP because it reduces magnification of mediastinal structures and provides better anatomical detail 3

Critical Limitation to Understand

• Plain X-rays miss up to 85% of fish bones, chicken bones, and other non-radiopaque objects in the gastrointestinal tract 1, 2
• The overall false-negative rate for esophageal foreign bodies reaches 47% on plain radiography 1, 2
• Bone fragments are particularly difficult to visualize on standard radiographs due to their small size and variable radiopacity 4

When Initial X-Rays Are Negative

Proceed Directly to CT Scan If:

• Patient remains symptomatic despite negative X-ray 1
• High clinical suspicion persists based on history and physical examination 1
• Any signs of perforation are present (fever, severe pain, peritoneal signs) 1

CT Scan Performance

• CT demonstrates 90-100% sensitivity and 93.7-100% specificity for detecting foreign bodies including bones 1, 2
• CT is essential for locating non-radiopaque objects and evaluating complications such as perforation, abscess formation, or obstruction 1, 2
• CT can identify subtle secondary signs of perforation that may be the only clue to a missed bone fragment 4

Timing of Endoscopy

Emergent Endoscopy (Within 2-6 Hours)

• Complete esophageal obstruction from any foreign body 1, 2
• Sharp-pointed bone fragments in the esophagus 1, 2

Urgent Endoscopy (Within 24 Hours)

• Esophageal foreign bodies without complete obstruction 1
• Persistent esophageal symptoms even with negative radiographic examination 2

Common Pitfalls to Avoid

• Never rely solely on negative X-rays to exclude a swallowed bone—the false-negative rate is unacceptably high 1, 2
• Do not delay CT imaging in symptomatic patients waiting for "observation"—complications like perforation worsen outcomes significantly 4
• Avoid assuming all bones are radiopaque—fish and chicken bones are frequently radiolucent 1, 4
• Do not skip lateral views—single frontal views miss significant pathology 3

Additional Workup for Symptomatic Patients

• Obtain CBC, CRP, and inflammatory markers if perforation is suspected 1
• Consider blood gas analysis and serum creatinine for patients requiring intervention 1