Barium Swallow Test: Purpose and Procedure
Primary Purpose
The barium swallow test (esophagram) is a fluoroscopic examination that simultaneously evaluates swallowing function, esophageal structure, and motility disorders in patients with dysphagia, odynophagia, or regurgitation. 1
Clinical Indications by Symptom Type
For Oropharyngeal Dysphagia
- Modified barium swallow (videofluoroscopic swallowing study) is the preferred test when structural abnormalities have been excluded by endoscopy, performed with a speech therapist to assess oral and pharyngeal swallowing phases, laryngeal penetration, and aspiration risk 2, 3
- This study identifies the cause of dysphagia in 76% of patients 2
- Critical warning: 55% of patients with aspiration lack a protective cough reflex (silent aspiration), making modified barium swallow essential for detection 3
For Retrosternal (Esophageal) Dysphagia
- Biphasic esophagram is the preferred initial imaging procedure, combining double-contrast views for mucosal detail with single-contrast prone views for structural assessment 2, 3
- This technique has 96% sensitivity for detecting esophageal and gastroesophageal junction carcinoma 2, 3
- Detects 95% of lower esophageal rings and peptic strictures, outperforming endoscopy which detects only 76% of rings 2, 3
Procedural Components
Biphasic Esophagram Technique
- Double-contrast views: Best detect mucosal lesions including tumors, esophagitis, and subtle inflammatory changes 2
- Prone single-contrast views: Patient continuously drinks low-density barium suspension to optimally detect lower esophageal rings and strictures (2-3 times more sensitive than upright views) 2
- Full evaluation: Includes pharynx, entire esophagus, and gastric cardia, as distal abnormalities can cause referred pharyngeal symptoms 2, 3
Modified Barium Swallow Protocol
- Evaluates various bolus consistencies (thin liquid, nectar, pudding, solid) to assess swallowing safety and efficiency 2
- Does not evaluate esophageal anatomy or structure, making it inappropriate as the sole test for retrosternal dysphagia 2
Diagnostic Capabilities
Structural Abnormalities Detected
- Esophageal carcinoma (96% sensitivity) 2
- Strictures, rings, and webs (95% sensitivity) 2
- Zenker diverticulum and pharyngeal tumors 2
- Infectious esophagitis (ulcers and plaques in immunocompromised patients) 2
Functional Disorders Assessed
- Esophageal motility disorders with 80-89% sensitivity and 79-91% specificity compared to manometry, including achalasia and diffuse esophageal spasm 2, 3
- Gastroesophageal reflux 2
- Pharyngeal dysmotility and aspiration risk 2
Clinical Algorithm
When to Use Which Study
For unexplained oropharyngeal dysphagia: Combined videofluoroscopy with static pharyngeal images plus complete esophageal evaluation provides higher diagnostic value than either study alone 3
For retrosternal dysphagia: Start with biphasic esophagram; if normal, endoscopy is not routinely warranted to rule out missed tumors 2
Post-surgical dysphagia: Single-contrast esophagram with water-soluble contrast if leak suspected, followed by barium if negative; modified barium swallow if dysmotility suspected 2
Immunocompromised patients: Biphasic esophagram more accurate than single-contrast for detecting infectious esophagitis 2
Critical Pitfalls to Avoid
- Never perform oral contrast studies in complete esophageal obstruction (inability to swallow saliva), as this increases aspiration risk; emergent endoscopy within 2-6 hours is required instead 3
- Always evaluate the entire esophagus and gastric cardia even when symptoms seem pharyngeal, as mid/distal esophageal abnormalities cause referred dysphagia 2, 3
- Barium studies occasionally reveal dysmotility not detected by manometry, including achalasia with complete lower esophageal sphincter relaxation 2
Complementary Role with Other Tests
- Barium swallow has higher sensitivity than endoscopy for subtle strictures and rings 3, 4
- Endoscopy remains superior for detecting mild reflux esophagitis and obtaining tissue specimens 2
- High-resolution manometry should follow barium studies showing motility disorders to further characterize the functional abnormality 2