Imaging for Swallowed Foreign Body in the Abdomen

Initial Imaging Approach

The World Journal of Emergency Surgery recommends ordering plain radiographs (anteroposterior and lateral views of chest, abdomen, and pelvis) as the initial imaging study, but proceeding directly to CT scan if the patient is symptomatic, has high clinical suspicion, or if plain films are negative but concern persists 1, 2
Plain radiography is the first-line imaging modality for suspected foreign body ingestion, with significant limitations that must be understood upfront, including false-negative rates reaching 47% for esophageal foreign bodies overall 1, 2

False-negative rates for esophageal foreign bodies overall reach 47% 2
Up to 85% false-negative rate for food bolus, fish bones, chicken bones, and non-radiopaque objects 2
A negative X-ray does NOT rule out foreign body ingestion 2

The World Journal of Emergency Surgery recommends proceeding directly to CT scan in symptomatic patients, suspected perforation, or high clinical suspicion with negative plain films 1, 2
CT scan should be performed without delay in symptomatic patients despite negative X-ray, suspected perforation, or persistent symptoms for >24-48 hours 2

CT scan has 90-100% sensitivity for detecting foreign bodies and 93.7-100% specificity 2
CT scan is superior for locating non-radiopaque objects and essential for evaluating complications (perforation, abscess, obstruction) 2

Obtain lateral AND anteroposterior views of chest, abdomen, and pelvis for plain radiographs 1
Use contrast-enhanced CT for suspected perforation in hemodynamically stable patients 1

Proceed to CT if plain films are negative but patient symptomatic, suspected non-radiopaque object, or any signs of perforation or obstruction 1, 2

Obtain complete blood count (CBC), C-reactive protein (CRP), serum creatinine, blood gas analysis (lactate, base excess), and inflammatory markers (procalcitonin if available) if perforation is suspected or patient requires intervention 2, 4, 5

Hemodynamically unstable patients should not delay surgical treatment to perform imaging investigations 1, 6