GI Imaging

Densities X-ray allows visualization of different densities -Air -Fat -Water -Metal

Visualization of the Esophagus Different density required for visualization i.e.: contrast

Contrast Agents Water Soluble – Gastrografin – Low-osmolality Inert – Barium sulfate

Single vs. Double Contrast Improved mucosal visualization

Fluoroscope Real-time x-ray video Multiple sequential images Spot films

Barium Studies (Video) Esophogram Barium Swallow UGI series Modified Barium Swallow

Gastroesophageal Reflux

GERD & Barium Visualization of refluxing barium Patient position Valsalva Usefulness is arguable

GERD Secondary Signs Hiatal Hernia (HH) Cricopharyngeus muscle spasm Reflux esophagitis Benign stricture Barrett’s esophagus Aspiration pneumonia

Hiatal Hernia Extension of stomach into chest through esophageal hiatus 2 types: – Sliding 95% – Para-esophageal 5%  Not associated with GERD May be more prominent when supine

Cricopharyngeous Muscle Posterior wall of pharyngoesophageal junction Normally relaxes with swallowing to allow passage of food Incomplete relaxation can be seen as protective mechanism in GER patients Smooth impression at C5-6 level

Cricopharyngeous Muscle Spasm

Reflux Esophagitis Begins distally Thickened folds May have associated linear ulcers

Benign Stricture Distal or mid-esophagus Smooth walls May be partially distensible

Barrett’s Esophagus In approx. 10% of untreated reflux patients Metaplasia of normal squamous epithelium to a gastric columnar epithelium Nodular or granular mucosa Look for focal ulceration, stricture, and cancer (15% or 30x increase)

Barrett’s Esophagus

Aspiration Pneumonia Appearance will vary with amount of aspirate, patient position, reaction to aspiration Often bilateral, associated atalectasis Posterior and basal areas more common

Aspiration Pneumonia

Aspiration

Esophageal Cancer

Detection Barium studies are not as sensitive as endoscopy, but more readily available Suspect cases referred on to endoscopy CT, MRI not suitable for screening

Barium Swallow Patterns 1. Annular constricting Most common Many variations 2. Polypoid mass 3. Infiltrative In submucosa, may simulate benign stricture 4. Ulcerated mass

Esophageal Cancer

Esophago- bronchial fistula

Tumor Staging CT most commonly used Endoscopic ultrasound in some centers

Computed Axial Tomography

CT Staging Wall thickness Infiltration of paraesophageal fat planes Regional invasion (trachea, pleura, pericardium, vertebrae etc…) Lymphadenopathy Distant Metastases

Normal CT

Invasive Cancer

Endoscopic Ultrasound Smaller lesions Assess wall involvement

Esophageal Motility

Normal Motility Best seen prone 3 phases: – Oral, pharyngeal, esophageal

Esophageal Phase Primary wave: – Initiated by swallowing reflex Secondary Wave: – As response to esophageal distension

Normal Swallow

Abnormal Motility Non-specific finding Seen in reflux esophagitis, radiation injury, caustic ingestion, myxedema, diabetes mellitus…

Corkscrew esophagus Tertiary esophageal waves – Non-propulsive – Corkscrew or beaded appearance

Scleroderma Fibrosis of smooth muscle Dilated esophagus with widely patent GEJ Resultant reflux Reflux esophagitis => ulceration => stricture (mild) => Barrett’s => neoplasm

Scleroderma

Achalasia Diffusely decreased or absent peristalsis Lower esophageal sphincter fails to relax Smooth, tapered distal esophageal narrowing Some passage of food in upright position

Achalasia

Neuromuscular Disorders Most common => stroke Parkinsonism, Alzheimer’s, multiple sclerosis, CNS neoplasms, traumatic injury Modified barium swallow

Zenker’s Diverticulum

Zenker’s Herniation at posterior midline above UES Horizontal & oblique fibers of inferior constrictor muscles => Killian’s dehiscence Associated incomplete cricopharyngeus muscle relaxation Neck at superior aspect of sac Midline, but lateral extension with growth

Zenker’s Diverticulum