title: Magnetic resonance imaging determination of tracheal orientation in normal children. Practical implications.
abstract: OBJECTIVE
  To determine normative anatomical data on the pediatric upper airway.
  
  
  METHODS
  Anatomical study of the trachea and surrounding structures in vivo using magnetic resonance imaging. Three-dimensional positions of the hyoid bone, sternum, skin, and trachea were determined. Tracheal angulation was measured from the vertical plane.
  
  
  METHODS
  One hundred children (53 males and 47 females) undergoing magnetic resonance imaging of the brain or chest.
  
  
  METHODS
  None.
  
  
  RESULTS
  Ages ranged from 2 days to 20.4 years, with a median of 6.05 years. Gender differences were not significant. The mean distance from the hyoid bone to the sternal notch was 63.0 mm (SD, 22.04 mm). The skin to anterior tracheal wall distance averaged 9.34 mm (SD, 3.29 mm), and tracheal diameter averaged 8.48 mm (SD, 2.88 mm). The trachea was not found to be a linear structure. An anterior angulation change of 9.9 degrees (SD, 7.89 degrees) was detected. The point of inflection was found to lie below the sternal notch in children younger than 2 years and above the notch in older children.
  
  
  CONCLUSIONS
  Normal anatomical data of the pediatric airway have been acquired using magnetic resonance imaging. Because the trachea exhibits a previously unknown anterior angulation, current design of tracheotomy tubes may not be ideal. Rigid tracheotomy tubes that do not conform to the anatomical structure of the trachea may be responsible for suprastomal collapse or innominate artery erosion.
authors.affiliation: Children's Hospital Medical Center, Department of Pediatric Otolaryngology and Maxillofacial Surgery, Cincinnati, Ohio, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Reed
authors.forename: D M
authors.initials: DM
authors.lastname: O'Connor
authors.forename: C M
authors.initials: CM
authors.lastname: Myer
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D012867:Skin / Q000033:anatomy & histology; D013249:Sternum / Q000033:anatomy & histology; D014132:Trachea / Q000033:anatomy & histology*; D014140:Tracheotomy / Q000295:instrumentation*