Barium Swallow & Oesophageal Radiology
Radiology · GIT · lean revision notes
Barium Swallow & Oesophageal Radiology
The barium swallow remains the workhorse contrast study for the pharynx and oesophagus, and NEET PG loves it because the answers hide in classic visual patterns — bird-beak, rat-tail, corkscrew, apple-core. This set of notes walks through technique, fluoroscopic anatomy, and every high-yield sign you must instantly recognise.
Contrast agents & technique
The "barium swallow" specifically images the pharynx and oesophagus; extend it through the stomach and duodenum and it becomes a barium meal. The patient swallows a barium sulphate suspension under real-time fluoroscopy, with spot films taken in frontal, oblique (right anterior oblique is best for the retrocardiac oesophagus) and lateral projections. A double-contrast study adds effervescent granules (CO₂) to coat the mucosa and distend the lumen — best for mucosal detail (early carcinoma, varices, web). A single-contrast study (barium only) better demonstrates motility, strictures and the overall calibre.
High-yield: If perforation or a tracheo-oesophageal fistula (TOF) is suspected, never use barium — it incites mediastinitis and granuloma. Use non-ionic water-soluble iso-osmolar contrast (e.g. iohexol). Classic teaching favoured Gastrografin (ionic, hyperosmolar), but if aspirated it causes fatal flash pulmonary oedema, so low-osmolar non-ionic agent is preferred when aspiration is possible.
| Clinical scenario | Contrast of choice |
|---|---|
| Routine dysphagia, suspected stricture/achalasia | Barium sulphate |
| Suspected perforation / anastomotic leak | Water-soluble non-ionic (iohexol) |
| Suspected TOF or high aspiration risk | Non-ionic iso-osmolar (NOT Gastrografin) |
| Mucosal detail (early Ca, varices, web) | Double-contrast barium |
| Motility / reflux assessment | Single-contrast + fluoroscopy + video |
A video-fluoroscopic swallow study (VFSS / modified barium swallow) with barium-coated solids and liquids is the investigation for oropharyngeal dysphagia and aspiration (stroke, neuromuscular disease), assessed jointly with a speech therapist.
Normal fluoroscopic anatomy & extrinsic impressions
On a normal frontal/oblique film the oesophagus shows three smooth indentations on its anterior/left wall:
- Aortic arch impression (left side, ~T4)
- Left main bronchus impression (just below the aortic knuckle)
- Left atrium impression (lower third)
High-yield: Widening or a posterior impression on the oesophagus by an enlarged left atrium (mitral stenosis) is a classic chest/oesophageal sign — barium swallow lateral view shows posterior displacement of the oesophagus. An aberrant right subclavian artery (arteria lusoria) produces a characteristic oblique posterior extrinsic impression and dysphagia lusoria.
Normal peristalsis is a primary stripping wave triggered by swallowing; secondary waves clear residue; tertiary contractions are non-propulsive, abnormal (seen in ageing "presbyoesophagus" and diffuse oesophageal spasm).
Classic radiological signs — the core of the topic
This is the highest-yield table in the chapter. Memorise the sign → diagnosis mapping.
| Radiological sign | Diagnosis |
|---|---|
| Bird-beak / rat-tail / pencil-tip smooth tapering | Achalasia cardia |
| Corkscrew / rosary-bead oesophagus | Diffuse oesophageal spasm (DES) |
| Apple-core / rat-tail (irregular shouldered) / annular constriction | Oesophageal carcinoma |
| Shouldered, irregular filling defect | Malignant stricture |
| Smooth, tapering, concentric narrowing | Benign (peptic) stricture |
| Mucosal shelf / web anteriorly in upper oesophagus | Plummer-Vinson (Paterson-Brown-Kelly) |
| Posterior midline outpouching at C5-C6 | Zenker (pharyngeal) diverticulum |
| Mid-oesophageal traction diverticulum | Mediastinal nodal scarring (old TB) |
| Worm-eaten / serpiginous filling defects in lower oesophagus | Oesophageal varices |
| Feline oesophagus (transverse folds) | GORD / eosinophilic oesophagitis |
| Schatzki ring at GO junction | Lower oesophageal ring + hiatus hernia |
Achalasia cardia
Failure of the lower oesophageal sphincter (LOS) to relax with aperistalsis of the body, due to loss of inhibitory ganglion cells of the myenteric (Auerbach) plexus → unopposed cholinergic tone. Primary (idiopathic) or secondary to Chagas disease (Trypanosoma cruzi).
Barium swallow: dilated, often sigmoid/tortuous oesophagus tapering to a smooth, symmetric "bird-beak" (rat-tail / pencil-tip) narrowing at the GO junction; absent primary peristalsis; air-fluid level with absent gastric air bubble on erect chest film.
Diagnosis flow: Dysphagia (to solids and liquids from the outset) → barium swallow shows bird-beak → upper GI endoscopy to exclude pseudoachalasia (malignancy at cardia) → high-resolution oesophageal manometry = GOLD STANDARD (shows incomplete LOS relaxation, integrated relaxation pressure >15 mmHg, aperistalsis; Chicago classification types I–III).
High-yield: Investigation of choice / confirmatory test for achalasia is manometry, not barium swallow. Barium is the initial screening test. Treatment: pneumatic balloon dilatation or laparoscopic Heller myotomy + fundoplication, or POEM (per-oral endoscopic myotomy). Long-standing achalasia raises squamous cell carcinoma risk.
Diffuse oesophageal spasm (DES)
Uncoordinated, simultaneous, non-propulsive (tertiary) contractions causing intermittent dysphagia and chest pain. Barium gives the classic "corkscrew" or "rosary-bead / shish-kebab" oesophagus. Manometry shows premature/simultaneous contractions with normal LOS relaxation. Treatment: calcium-channel blockers, nitrates, CCB / botulinum toxin, peppermint oil.
Oesophageal carcinoma
Two dominant histologies:
| Feature | Squamous cell carcinoma | Adenocarcinoma |
|---|---|---|
| Commonest site | Middle third | Lower third / GO junction |
| Key risk factors | Smoking, alcohol, hot beverages, achalasia, Plummer-Vinson, lye stricture, tylosis | Barrett oesophagus, chronic GORD, obesity |
| Worldwide trend | Falling (still commonest globally/India) | Rising (commonest in West) |
Barium swallow: irregular "apple-core" / annular constricting lesion with shouldered margins, mucosal destruction, and an eccentric "rat-tail" narrowing (irregular, unlike the smooth rat-tail of achalasia). May show proximal dilatation.
Diagnosis flow: dysphagia (progressive, solids → liquids, weight loss) → barium swallow apple-core → endoscopy + biopsy = diagnostic gold standard → endoscopic ultrasound (EUS) for T and N staging (best for local depth/nodes) → CECT chest+abdomen / PET-CT for distant metastasis (M staging).
High-yield: Best investigation to confirm carcinoma = endoscopy with biopsy. Best for locoregional (T/N) staging = EUS. Best for distant metastasis / restaging = PET-CT.
Plummer-Vinson syndrome
Triad of dysphagia + iron-deficiency anaemia + oesophageal web (upper, anterior, post-cricoid), classically in middle-aged women; glossitis, angular cheilitis, koilonychia. Also called Paterson-Brown-Kelly syndrome. Barium shows a thin anterior mucosal shelf/web. Premalignant → post-cricoid squamous cell carcinoma.
Pharyngeal (Zenker) diverticulum
A pulsion, false diverticulum (mucosa + submucosa only) herniating posteriorly through Killian's dehiscence — the weak triangle between the oblique thyropharyngeus and transverse cricopharyngeus fibres of the inferior constrictor. Cause: cricopharyngeal incoordination/raised pressure.
Features: elderly patient, oropharyngeal dysphagia, regurgitation of undigested food, halitosis, gurgling neck swelling, recurrent aspiration.
Barium swallow (investigation of choice) shows a posterior midline outpouching at the pharyngo-oesophageal junction (~C5-C6).
High-yield: Do NOT do blind endoscopy first in suspected Zenker — risk of perforating the pouch. Barium swallow is the safe diagnostic test. Treatment: cricopharyngeal myotomy ± diverticulectomy, or endoscopic stapling. Long-standing pouch → rare squamous cell carcinoma (Zenker's).
Diverticulum types to compare:
| Type | Location | Nature | Mechanism |
|---|---|---|---|
| Zenker | Pharyngo-oesophageal (C5-6) | False (pulsion) | Cricopharyngeal dysfunction |
| Traction | Mid-oesophagus | True (all layers) | Adhesions from mediastinal nodes (old TB) |
| Epiphrenic | Distal, above diaphragm | False (pulsion) | Associated motility disorder/achalasia |
Hiatus hernia
Herniation of the stomach through the oesophageal hiatus of the diaphragm.
| Type | Name | GO junction | Notes |
|---|---|---|---|
| Type I (~95%) | Sliding | Displaced above diaphragm | Associated with GORD; commonest |
| Type II | Rolling / para-oesophageal | Normal position | Gastric fundus herniates beside oesophagus; risk of strangulation/volvulus |
| Type III | Mixed | Above | Sliding + para-oesophageal |
| Type IV | — | — | Other organ (colon/spleen) in sac |
Barium swallow: gastric rugal folds and the "B-ring (Schatzki ring)" above the diaphragm; supradiaphragmatic gastric pouch. A retrocardiac air-fluid level on chest X-ray is a clue.
High-yield: Sliding hiatus hernia → reflux symptoms, managed medically/anti-reflux surgery. Para-oesophageal (rolling) hernia is the dangerous one — even if asymptomatic it may need repair because of gastric volvulus/strangulation.
Oesophageal varices, webs, rings & strictures
- Varices: dilated submucosal veins (portal hypertension) → "worm-eaten" serpiginous filling defects in the lower oesophagus on barium; but endoscopy is investigation of choice (also therapeutic — banding).
- Schatzki ring: thin mucosal ring at the squamo-columnar junction; symptomatic when lumen <13 mm → intermittent solid-food dysphagia ("steakhouse syndrome").
- Benign (peptic) stricture: smooth, tapering, concentric narrowing in distal oesophagus from chronic reflux.
- Malignant stricture: irregular, eccentric, shouldered, mucosal destruction.
- Eosinophilic oesophagitis: ringed ("feline"/trachealised) oesophagus, small-calibre oesophagus; biopsy ≥15 eosinophils/HPF.
Caustic/corrosive injury & motility in systemic disease
- Corrosive (acid/alkali) ingestion: acute phase — never instrument early; later barium shows long, smooth tapering strictures (often multiple). Alkali → liquefactive necrosis (worse, transmural); acid → coagulative. Marked future SCC risk.
- Scleroderma (systemic sclerosis): smooth muscle atrophy/fibrosis → dilated, aperistaltic lower two-thirds with a patulous (incompetent) LOS → free reflux and peptic stricture (contrast achalasia's tight LOS). Barium: dilated oesophagus that freely refluxes — opposite of achalasia.
Approach to dysphagia (stepwise)
Dysphagia → localise: oropharyngeal (difficulty initiating, nasal regurgitation, aspiration) vs oesophageal → solids only = mechanical/obstructive (stricture, ring, carcinoma) vs solids + liquids = motility (achalasia, DES, scleroderma) → barium swallow for pattern → endoscopy ± biopsy for mucosal/mass lesions → manometry for motility disorders → stage/treat.
High-yield: Progressive dysphagia (solids → liquids) + weight loss in an older smoker = carcinoma until proven otherwise → endoscopy + biopsy. Intermittent, non-progressive dysphagia to solids = ring/web. Dysphagia to both solids and liquids from onset = motility disorder (achalasia).
Complications quick-reference
- Achalasia: aspiration pneumonia, oesophagitis, SCC (5%), megaoesophagus.
- Carcinoma: TOF, obstruction, mediastinal invasion (RLN palsy → hoarseness), metastasis.
- Zenker: aspiration, perforation on instrumentation, malnutrition, rare SCC.
- Para-oesophageal hernia: gastric volvulus, strangulation, Cameron ulcers (anaemia).
- Barrett (from GORD): dysplasia → adenocarcinoma.
Recently asked / exam angle
- Sign-spotting MCQs: "Bird-beak appearance on barium swallow" → achalasia; "Corkscrew oesophagus" → DES; "Rat-tail/apple-core with shouldering" → carcinoma; "Worm-eaten lower oesophagus" → varices.
- Investigation of choice questions: confirmatory test for achalasia = manometry; for Zenker = barium swallow (NOT endoscopy first); for carcinoma diagnosis = endoscopy + biopsy; locoregional staging = EUS; metastasis = PET-CT.
- Contrast questions: suspected perforation/TOF → water-soluble non-ionic contrast, never barium; aspiration risk → avoid hyperosmolar Gastrografin.
- Anatomy: Zenker through Killian's dehiscence (between thyropharyngeus & cricopharyngeus). Three normal indentations = aorta, left main bronchus, left atrium.
- Hernia: sliding (Type I) commonest & refluxes; para-oesophageal (Type II) → strangulation/volvulus risk.
- Eponym matching: Plummer-Vinson = web + IDA + dysphagia (post-cricoid SCC); Schatzki ring <13 mm; Barrett = columnar metaplasia → adenocarcinoma; arteria lusoria → dysphagia lusoria.
- Image-based question (NExT pattern): given a barium swallow image of a dilated oesophagus with smooth distal tapering and air-fluid level — identify achalasia and pick manometry as next step.
Mnemonics:
- Bird-Beak = Benign smooth taper (achalasia); Apple-core = Abrupt, Abnormal margins (cancer).
- Zenker = "Z" for elderly who regurgitate undigested food + halitosis; remember Killian's dehiscence (think "Killer pouch — don't scope blindly").
- Achalasia "both And liquids from onset" — motility, not mechanical.
Rapid revision
- Bird-beak (rat-tail/pencil-tip) smooth taper + dilated oesophagus + absent gastric bubble = achalasia; gold-standard test = manometry.
- Corkscrew/rosary-bead oesophagus = diffuse oesophageal spasm.
- Apple-core / irregular shouldered narrowing with mucosal destruction = oesophageal carcinoma; confirm by endoscopy + biopsy.
- EUS = best for T/N staging; PET-CT = best for distant metastasis.
- SCC = middle third, smoking/alcohol/Plummer-Vinson/achalasia/caustic; adenocarcinoma = lower third, Barrett/GORD.
- Suspected perforation/TOF → water-soluble non-ionic contrast, never barium; avoid hyperosmolar Gastrografin if aspiration risk.
- Zenker diverticulum = posterior pulsion (false) pouch through Killian's dehiscence; diagnose with barium swallow, NOT blind endoscopy.
- Traction diverticulum = mid-oesophageal true diverticulum from old TB nodes; epiphrenic = distal, motility-associated.
- Sliding hiatus hernia (Type I, 95%) → reflux; para-oesophageal (Type II) → strangulation/volvulus risk.
- Plummer-Vinson = web + iron-deficiency anaemia + dysphagia → post-cricoid SCC; Schatzki ring symptomatic <13 mm.
- Scleroderma = dilated aperistaltic oesophagus with patulous LOS and free reflux (opposite of achalasia's tight LOS).
- Varices = worm-eaten lower-oesophageal filling defects on barium, but endoscopy is investigation of choice (and therapeutic).