Croup

  • Etiology: Parainfluenza virus most common pathogen
  • Imaging: Glottic and subglottic process
    — AP radiograph: Symmetric subglottic narrowing in the first 1-2 centimeters of the trachea leading to loss of normal shoulders of subglottic trachea due to subglottic edema = (church) steeple sign
    — Lateral radiograph: Distension of hypopharynx with normal epiglottis and areyepiglottic folds and narrowing or loss of definition of subglottic trachea
  • DDX:
  • Complications:
  • Treatment:
  • Clinical:
    — Average age 12 months
    — Most common cause acute upper airway obstruction in 6 months – 3 years
    — Symptoms are barky cough due to vocal cord involvement, mild fever, shortness of breath, inspiratory stridor, no dysphagia

Radiology Cases of Croup

Radiology Cases of Croup Compared to Normal

Radiograph of croup
AP radiograph of the airway (right) shows symmetric subglottic narrowing of the trachea leading to loss of the normal shoulders of the subglottic trachea (church steeple sign). AP radiograph of a normal airway for comparison (left) shows the normal shoulders of the subglottic trachea.
Radiograph of croup
AP radiograph of the airway (left) shows symmetric subglottic narrowing in the first several centimeters of the trachea leading to loss of the normal shoulders of the subglottic trachea (steeple sign) due to subglottic edema. AP radiograph of the now normal airway taken a month after the resolution of symptoms (right) shows clear delineation of the normal shoulders of the subglottic trachea.

Radiology Cases of Croup

Radiographs of croup
AP + lateral radiographs of the airway show narrowing of the subglottic trachea (steeple sign) and overdistension of the hypopharynx.
Radiograph of croup
AP radiograph of the airway (left) shows loss of the normal shoulders of the subglottic trachea (steeple sign). Lateral radiograph of the airway (right) shows distension of the hypopharynx, a normal epiglottis and some narrowing of the subglottic trachea.
Radiograph of croup
AP radiographs of the airway in inspiration (left) and expiration (right) show symmetric subglottic narrowing of the proximal trachea (left) leading to the loss of the normal shoulders of the subglottic trachea due to subglottic edema (church steeple sign).

Endoscopy Cases of Croup

Endoscopic image of croup
Series of endoscopic images of the airway show persistent narrowing of the subglottic trachea.
Endoscopy image of croup
Endoscopic image of the airway shows mild sublglottic edema.