• Soft tissue measurements on the lateral neck image
  • At C3: <3 mm (less than 1/3 AP diameter)
  • At C6: < the AP width of C6 vertebral body
• Retropharyngeal Space
  • Contains lymphatics that drain
    • Nasopharynx
    • Adenoids
    • Posterior nasal sinuses
  • These chains atrophy after age 4
• Retropharyngeal abscess
  • Almost all occur before age 6
  • 50% between 6-12 months
  • Most common pathogens are
    • Staph aureus
    • Group A Beta hemolytic Strep
    • Hemophilus
  • Clinically
    • Prodromal nasopharyngitis
    • Severe throat pain with drooling
    • Dysphagia
    • Hyperextension of the head
    • “Hot potato” muffled voice
  • In adults, usually 2° trauma to oropharynx
    • Iatrogenic
    • Perforated FB
• Retropharyngeal perforation
  • Causes
    • Trauma to esophagus or trachea
    • Penetrating injuries from weapons
    • Perforation from within
      • Chicken bone
      • Mediastinal emphysema tracking into neck
    • Retropharyngeal abscess 2° gas-forming organism
• Imaging findings of retropharyngeal perforation
  • Streaks of air in soft tissues of neck
  • Anterior displacement of pharynx
  • Associated pneumothorax possible
  • Cervical or mediastinal air seen in 60% of cases of ruptured esophagus
• Upper airway infections-The Big Two
  • Croup
  • Epiglottitis
• Croup                   
  • Laryngotracheobronchitis
  • Usually viral
  • May be difficult to distinguish from early retropharyngeal abscess
  • Occurs at age 6 months to 2 years
    • Younger than epiglottitis
  • The three major findings of croup
    • Distension of the hypopharynx
    • Distension of the laryngeal ventricle
    • Haziness or narrowing of subglottic space

Soft tissue lateral neck (edge enhanced) shows a slightly dilated hypopharynx (red arrow),
dilatation of the laryngeal ventricle (white arrow) and narrowing of the sub-glottic trachea (blue arrow)
For the same image without the arrows, click here

• Epiglottitis
  • Most commonly H. flu type B
  • Peak incidence now closer to 6-7 years
    • Croup occurs from 6 months to 2 years
  • Lateral radiograph -- erect position only
    • Supine position may close off airway
  • Imaging findings
    • Epiglottis is enlarged
    • Appears thumb-like
    • Aryepiglottic folds are thickened
    • Pre-epiglottic space (vallecula) is smaller than normal
      • In many cases, it’s obliterated
• Impacted esophageal foreign bodies
  • Food or true foreign bodies
    • Chicken bones (opaque), fish bones (non-opaque)
    • Coins, toy trucks
  • Most often they impact just below cricopharyngeous (70%)
    • Another 20% impact at the level of the aortic arch
    • Another 10% at EG junction
    • Once past the esophagus, most foreign bodies will pass through the GI tract
  • Clinical findings of an impacted esophageal foreign body
    • Dysphagia and odynophagia most commonly
    • Even if FB passes, many complain of pain referable to cervical esophagus
  • Always check for lead lines in children
    • Pica
  • Chicken bones are usually opaque
    • Fish bones contain less calcium and usually are not
  • Plain films usually do not demonstrate the FB but are still obtained first
    • If negative, then either contrast esophagram or CT if high index of suspicion
  • Treatment
    • Removal is most often performed using endoscopy
    • Temporization and surgery are other options
    • An ingested button battery lodged in esophagus must be removed immediately
  • Complications of an impacted foreign body
    • Perforation
      • Longer the FB remains impacted (>24hrs), higher incidence of perforation
    • Stricture
    • Diverticulum formation