What is a biphasic esophagram?

What is a Biphasic Esophagram?

A biphasic esophagram is a fluoroscopic barium study that combines upright double-contrast views (using high-density barium to coat the esophageal mucosa) with prone single-contrast views (using low-density barium to detect structural abnormalities), providing comprehensive evaluation of both mucosal detail and structural/functional esophageal abnormalities. 1

Technical Components

The biphasic technique consists of two distinct phases that complement each other:

Double-contrast phase:

• Uses high-density barium suspension in the upright position to coat the esophageal mucosa 1
• Provides superior mucosal detail for detecting inflammatory diseases and neoplastic lesions 1
• Achieves 96% sensitivity for diagnosing esophageal carcinoma 1
• Detects mucosal abnormalities including fine nodularity, granularity, erosions, ulcers, and thickened longitudinal folds 2

Single-contrast phase:

• Uses low-density barium suspension in the prone position 1, 3
• Optimizes detection of structural abnormalities including hiatal hernias, lower esophageal rings, and strictures 1, 3
• Achieves approximately 95% detection rate for lower esophageal rings and peptic strictures 1

Diagnostic Performance

The combined biphasic technique outperforms either method alone:

• Achieves 88% sensitivity for detecting reflux esophagitis, compared to 77% for single-contrast alone and 80% for double-contrast alone 2, 1
• Provides 80-89% sensitivity for diagnosing esophageal motility disorders including achalasia and diffuse esophageal spasm 1
• Simultaneously evaluates swallowing function, esophageal motility, gastroesophageal reflux, and structural abnormalities 4

Clinical Indications

The American College of Radiology recommends biphasic esophagram as the preferred initial imaging for:

• Retrosternal dysphagia 1
• Unexplained oropharyngeal dysphagia 1
• Suspected acid reflux, esophagitis, or peptic ulcer disease 1
• Immunocompromised patients with dysphagia or odynophagia 1
• Pre-operative evaluation for antireflux surgery (all patients require barium esophagram per American College of Surgeons consensus) 2
• Suspected hiatal hernia (biphasic esophagram is "usually appropriate" as initial imaging) 2

Anatomic and Functional Information Provided

The biphasic esophagram provides comprehensive assessment including:

• Esophageal length and anatomic configuration 2
• Presence, size, and type of hiatal hernias (superior to endoscopy for differentiating sliding from paraesophageal hernias) 2
• Esophageal strictures and their severity 2
• Presence and degree of gastroesophageal reflux 2
• Reflux esophagitis manifestations (nodularity, erosions, thickened folds, inflammatory polyps, scarring) 2
• Lower esophageal rings 2
• Esophageal motility patterns 1, 3

Important Clinical Caveats

Patient cooperation requirements:

• Optimal biphasic examination requires patient cooperation for positioning and swallowing maneuvers 1
• Elderly, debilitated, or obese patients may require single-contrast technique only 1

Limitations compared to endoscopy:

• Endoscopy remains superior for detecting mild reflux esophagitis and other subtle forms of esophagitis 1
• Tissue diagnosis requires endoscopy with biopsy when histologic confirmation is needed 1, 5
• However, barium studies have superior sensitivity for detecting structural pharyngeal abnormalities like Zenker's diverticulum compared to endoscopy 6

When to extend evaluation:

• If the hiatal hernia is large, a complete upper GI series evaluation should be included for full assessment of the stomach 2
• Complete esophageal evaluation is essential even when pharyngeal symptoms predominate, as one-third of patients with dysphagia have abnormalities only in the esophagus 1