Gi imaging Densities x-ray allows visualization of different densities

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

• Annular constricting

• Most common
• Many variations

• Polypoid mass

• Infiltrative

• In submucosa, may simulate benign stricture

• Ulcerated mass

Esophageal Cancer

Esophago-bronchial fistula

Tumor Staging

• CT most commonly used

• Endoscopic ultrasound in some centers

Computed Axial Tomography

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

Zenker’s Diverticulum