Stridor and upper airway obstruction in infants and children.

Upper airway obstruction in infants and children is a common and distressing problem because of the relatively narrow diameter of the airway in early life. Although ultrasound, computed tomography, and magnetic resonance imaging have become increasingly popular modalities for use in many pediatric diseases, plain radiography and fluoroscopy, with attention to technique, collimation, and patient position, continue to be the mainstays for the evaluation of stridor in children. An understanding of normal airway anatomy and air flow dynamics is necessary for this evaluation. This article presents the diagnostic features of conditions a radiologist may encounter in an infant or child with upper airway obstruction. Plain radiographic and fluoroscopic findings from over 100 cases of infants and children with this condition were reviewed to determine how frequently the specific diagnosis was confirmed with these studies. In the vast majority of cases, plain radiography and fluoroscopy suffice.