Upper GI & Barium Swallow Fluoroscopic Studies
Overview & Contrast Media
Upper GI (UGI) and barium swallow fluoroscopic studies are contrast examinations of the esophagus, stomach, and duodenum. These are high-yield ARRT topics that test your knowledge of contrast selection, patient preparation, and fluoroscopic technique.
Definition: An esophagram (barium swallow) examines the esophagus from the pharynx to the stomach. An Upper GI series extends coverage to include the stomach and duodenum.
Contrast Media Options
- Barium sulfate — positive contrast agent (radiopaque); high-density suspension that coats the mucosal surface. Used in the majority of UGI studies.
- Water-soluble contrast (Gastrografin) — used when perforation is suspected. Barium is contraindicated if perforation is possible, as it causes severe peritoneal inflammation.
Exam Trap: If a question describes a patient with suspected bowel perforation, the correct contrast agent is water-soluble contrast (Gastrografin), NOT barium sulfate. This is a frequently tested contraindication.
Single-Contrast vs. Double-Contrast Technique
| Technique | What Is Used | Best For |
|---|---|---|
| Single-contrast | Barium alone | Filling defects, motility, gross anatomy |
| Double-contrast (air-contrast) | Barium + air (CO₂) | Mucosal detail, early lesions, ulcers |
In double-contrast technique, the patient ingests effervescent granules or CO₂ to distend the stomach with air while barium coats the mucosa — providing superior mucosal detail for detecting early pathology.
Patient Preparation: The patient must be NPO for 8 hours before the exam to ensure the stomach is empty and barium coating is not diluted by food or fluid.
Key Anatomical Structures Evaluated
- Esophagus — pharynx to gastroesophageal junction (GEJ)
- Fundus — superior portion of the stomach (left side; posterior when supine)
- Body — main portion of the stomach
- Antrum — distal stomach (right side; anterior when supine)
- Pylorus, pyloric canal, pyloric valve — gastric outlet
- Duodenal bulb (D1) — first portion of duodenum
- Descending duodenum / C-loop (D2)
- Horizontal duodenum (D3)
- Ascending duodenum (D4)
Positioning Tip: When the patient is supine, the fundus fills with barium (posterior/dependent) and the antrum/pylorus fill with air (anterior). When prone (PA), the antrum and pylorus fill with barium — making the PA projection ideal for demonstrating the duodenal bulb.
Positioning & Projections
During the esophagram, the patient drinks barium while fluoroscopy is performed in real time. Overhead spot images supplement the fluoroscopic images. The following projections are standard:
Esophagram Projections
| Projection | Position / Rotation | Demonstrates |
|---|---|---|
| AP | Patient supine or upright, no rotation | Esophagus overlying spine |
| RAO (preferred) | 35–40° right anterior oblique | Esophagus projected between heart and vertebral column — free of superimposition |
| Lateral | True lateral, left side against IR | Retrosternal esophagus, anterior/posterior displacement |
Key Positioning Fact: The RAO projection at 35–40° is the preferred oblique for the esophagram because it projects the esophagus free of the vertebral column and away from the heart, providing the clearest view of the esophageal lumen.
Common Error: Using an LAO instead of RAO for the esophagram will superimpose the esophagus over the vertebral column, obscuring mucosal detail. The RAO is the standard oblique for esophageal studies.
The UGI series evaluates the esophagus, stomach, and duodenum. Multiple positions are used to coat all mucosal surfaces with barium. The patient turns and rolls between positions to distribute barium evenly.
UGI Projections Summary
| Projection | Rotation / Position | Primary Demonstration |
|---|---|---|
| RAO (primary) | 35–40° RAO | 5-point stomach: body, antrum, pylorus, duodenal bulb, duodenal loop; primary position for double-contrast UGI |
| PA (prone) | Prone, no rotation | Duodenal bulb and C-loop (barium fills antrum/pylorus in prone) |
| Left lateral | True left lateral | Pylorus, duodenum, retrogastric space |
| AP (supine) | Supine, no rotation | Fundus (barium-filled), body of stomach |
| LPO | Left posterior oblique | Fundus and body in double-contrast (air fills fundus) |
The 5-Point Stomach (RAO position): The RAO at 35–40° demonstrates all five key gastric landmarks in a single image: body, antrum, pylorus, duodenal bulb, and duodenal loop. This is the most tested UGI position on the ARRT exam.
Positioning Trap: The left lateral position specifically demonstrates the retrogastric space — the area posterior to the stomach. Do not confuse this with the right lateral, which is not a standard UGI position.
Spot films are taken of the duodenal bulb and mucosal folds during fluoroscopy. Overhead (non-fluoroscopic) images are obtained after fluoroscopy to document the stomach and duodenum in full barium fill.
Pathology & Image Documentation
UGI and barium swallow studies are performed to evaluate a wide range of pathological conditions. The ARRT exam tests recognition of classic fluoroscopic findings and the best position to demonstrate each condition.
Key Pathological Findings
- Hiatal hernia — prolapse of the stomach through the esophageal hiatus; best demonstrated with the patient in the head-down (Trendelenburg) position to increase intra-abdominal pressure.
- Gastric ulcers — mucosal outpouching on the lesser curvature; seen as a niche or crater on barium studies.
- Duodenal ulcers — most common in the duodenal bulb; demonstrated on PA and RAO projections.
- Gastric carcinoma — classic apple-core lesion (irregular filling defect with shouldering).
- Esophageal strictures — narrowing of the esophageal lumen; demonstrated on RAO esophagram.
- Achalasia — failure of the lower esophageal sphincter to relax; classic appearance is a dilated esophagus with bird-beak narrowing at the GEJ.
- Barrett's esophagus — metaplastic change of esophageal mucosa; associated with chronic GERD.
Exam Tip: Hiatal hernia is best demonstrated with the patient in the head-down (Trendelenburg) position. If the question asks which position best shows a hiatal hernia, the answer is head-down/Trendelenburg — not upright.
Image Documentation Protocol
- Initial fluoroscopic spot images are taken during barium passage in real time.
- Overhead (non-fluoroscopic) images supplement fluoroscopic images after barium has filled the stomach and duodenum.
- Document: filling defects, mucosal irregularities, and obstruction.
- Patient turns and rolls between positions to coat the gastric mucosa evenly with barium.
Key Concepts Summary
⚠ KEY CONCEPTS — Test-Ready Recall
- Contrast selection: Use barium sulfate for routine studies; use water-soluble contrast (Gastrografin) when perforation is suspected.
- Patient prep: NPO for 8 hours before the exam.
- Esophagram oblique: RAO at 35–40° projects the esophagus free of the spine and heart — the preferred oblique.
- UGI primary position: RAO at 35–40° demonstrates the 5-point stomach (body, antrum, pylorus, duodenal bulb, duodenal loop).
- PA (prone) position: Best demonstrates the duodenal bulb and C-loop.
- Left lateral position: Demonstrates the pylorus, duodenum, and retrogastric space.
- Hiatal hernia: Best seen with patient in head-down (Trendelenburg) position.
- Achalasia: Classic finding = dilated esophagus with bird-beak narrowing at the GEJ.
- Double-contrast technique: Barium + air (CO₂) — superior mucosal detail; RAO is the primary position.
- Supine vs. prone: Supine → fundus fills with barium (posterior/dependent); prone → antrum/pylorus fill with barium (anterior becomes dependent).
- Common error: Using LAO instead of RAO for the esophagram superimposes the esophagus over the spine.
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