Barium Studies - A Comprehensive Overview

1. The Contrast Agent: Barium Sulfate

• Chemical: Barium sulfate (BaSO₄) - an insoluble, inert salt that is not absorbed from the GI tract
• Property: Strongly radio-opaque due to high atomic number of barium
• Formulations: Available as suspensions of varying density (35-40% weight/volume for small bowel follow-through, higher densities for double-contrast studies)
• Safety: Non-toxic because it is not absorbed. However, if it leaks into the peritoneal cavity or mediastinum (e.g. perforation), it causes severe chemical peritonitis/mediastinitis - a life-threatening complication
• Alternative - Water-soluble contrast (e.g. Gastrografin/iodinated contrast): Used when perforation is suspected (pharynx, esophagus, bowel anastomosis). Water-soluble agents are absorbed and excreted without the risk of barium peritonitis. Note: Gastrografin is hypertonic and contraindicated if aspiration risk is high (causes pulmonary edema)

2. Techniques: Single vs. Double Contrast

1. Mucosal relief views - small volume barium in collapsed/partially collapsed lumen, shows mucosal fold pattern
2. Barium-filled views - large volume fills lumen completely; good for gross lesions
3. Double-contrast views - thin barium coating + gas distension; superior for subtle mucosal lesions

3. Types of Barium Studies

A. Barium Swallow (Esophagogram)

• Patient drinks liquid barium; fluoroscopic images taken in multiple projections
• Motility assessed with multiple single swallows in different positions, including recumbent (to assess peristalsis without gravity effect)
• Continuous and single swallows observed separately (a second swallow obliterates peristalsis of the first)
• The oesophageal lumen is distended with liquid barium, or coated with thick barium and distended by gas to show intrinsic irregularities and extrinsic impressions

Normal esophagogram - Cummings Otolaryngology

• Dysphagia (oropharyngeal and esophageal)
• Suspected esophageal stricture, web, ring (Schatzki's ring)
• Hiatal hernia - assessment of presence and reducibility
• Achalasia and esophageal motility disorders
• Suspected esophageal diverticulum (e.g. Zenker's)
• GERD evaluation - spontaneous reflux of barium into proximal esophagus is highly specific for reflux (though not sensitive)
• Pre-operative assessment of esophageal peristalsis before antireflux surgery
• Assessment for esophageal leiomyoma (appears as smooth, semilunar/crescent-shaped filling defect)

• Barrett's esophagus cannot be reliably assessed
• Mild esophagitis frequently missed
• Not adequate for mucosal biopsies
• Both pharynx and esophagus should be examined even if complaint is only esophageal (35% of patients have simultaneous disorders of both)

B. Modified Barium Swallow (MBS) / Videofluoroscopic Swallow Study (VFSS)

• Focuses on oral and pharyngeal phases of swallowing (not primarily the esophagus)
• Performed jointly with a speech-language pathologist
• Entire examination is videotaped (real-time fluoroscopic recording)
• Performed primarily in lateral projection (frontal supplemented for piriform sinus symmetry)

• Patient given barium suspensions of several consistencies: thin liquid, thick liquid, paste, and solid
• Speech pathologist administers boluses while radiologist observes fluoroscopically
• If aspiration or laryngeal penetration is identified with neutral head position, protective maneuvers are tested: chin tuck, neck turn, postprandial forced cough

Normal pharyngogram - Cummings Otolaryngology

C. Barium Meal (Upper GI Series)

• Double-contrast technique is standard: patient ingests effervescent granules to produce gas, then swallows high-density barium
• Multiphasic study: double-contrast views (upright), single-contrast compression views (prone), mucosal relief views
• Spot images of all mucosal surfaces in multiple positions
• Important for duodenum: Double-contrast views are supplemented with prone compression views (low-density barium) because up to 50% of duodenal ulcers are on the anterior wall - not optimally coated in supine position

• Suspected peptic ulcer disease (gastric or duodenal ulcer)
• Epigastric pain, nausea, vomiting
• Suspected gastric carcinoma
• Suspected esophagogastric junction pathology
• Gastric outlet obstruction
• Post-surgical anatomy assessment
• Hiatal hernia

• Gastric ulcers: primarily on lesser curvature or posterior wall
• Duodenal ulcers: up to 50% on anterior wall
• Linitis plastica (leather-bottle stomach): reduced distensibility due to diffuse gastric infiltration
• "Apple core" or "shouldering" lesion: carcinoma

D. Small Bowel Follow-Through (SBFT) / Barium Small Bowel Series

• Patient ingests 500-600 mL of a 35-40% (weight/volume) barium sulfate suspension
• Serial overhead abdominal radiographs at timed intervals
• Fluoroscopy is the primary examination method - periodic spot imaging of jejunum and ileum with manual palpation and abdominal compression to separate overlapping loops
• Examination continues until all loops including terminal ileum are demonstrated

Normal Enteroclysis Examination - Grainger & Allison's Diagnostic Radiology

• Suspected Crohn's disease (terminal ileal disease)
• Small bowel obstruction (intermittent or low-grade)
• Malabsorption evaluation
• Suspected small bowel tumor
• Radiation enteropathy
• Surgical anatomy planning

• CT/MR enterography has largely replaced SBFT for most indications
• Unreliable without fluoroscopy - overhead-only technique misses many lesions due to overlapping loops
• Radiation exposure

E. Enteroclysis (Small Bowel Enema)

• A tube is passed nasally into the proximal small bowel (beyond the ligament of Treitz)
• Barium + methylcellulose + air are instilled at controlled rates
• This achieves optimal bowel distension - the key advantage over SBFT
• Double-contrast technique (air after contrast agent) outlines mucosa and walls in superior detail

• Controlled bowel distension - superior mucosal detail
• Excellent for subtle mucosal changes (early Crohn's, malabsorption)
• Diagnostic yield: 10-25% for small bowel bleeding (vs. 0-6% for standard SBFT)

• Uncomfortable for the patient (requires nasoenteric intubation)
• Technically demanding - requires expertise
• Greater radiation exposure than SBFT
• Rarely performed in modern practice due to availability of VCE and CT/MR enterography

F. Barium Enema (Large Bowel Enema)

• Entire colon filled with low-density barium under fluoroscopic control
• Extensive palpation and compression during filling
• Post-evacuation radiograph for mucosal detail
• Preferred for: suspected obstruction, acute diverticulitis, fistulas, elderly/debilitated patients

• Small volume high-density barium → coat mucosa → insufflation of air → distension
• Superior for: polyps, early IBD changes, rectal lesions, flexures, rectum
• Overall accuracy: ~95% for colorectal cancer detection

• Detection of colorectal polyps and cancer
• IBD - type, extent, severity
• Diverticular disease and complications
• Extrinsic mass lesions involving the colon
• Evaluation of the rectum
• Incomplete colonoscopy (to visualize proximal colon)
• Suspected Hirschsprung's disease (confirms presence; manometry and histology needed for definitive diagnosis)
• Megacolon/megarectum, redundant sigmoid

• Polyp detection rates: 32% for adenomas <6 mm, 53% for 6-10 mm, 48% for >10 mm (National Polyp Study)
• False-positive rate: 5-10% (inadequate bowel prep, diverticulosis mimicking polyps)
• False-negative rate: 10% (diverticulosis, redundant bowel, poor mucosal coating)
• Fails to detect 50% of polyps >10 mm (making it inadequate as a standalone screening tool)
• No role in LGI bleeding - cannot demonstrate vascular lesions; may delay angiography by impairing visualization
• Largely replaced by colonoscopy and CT colonography for screening

4. Contraindications

5. Comparison with Other Modalities

6. Radiation Dose Considerations

• Simple barium swallow: relatively low
• Small bowel follow-through/enteroclysis: moderate (prolonged fluoroscopy time)
• Barium enema: moderate

7. Summary of Clinical Applications by Region