Abstract
We performed respiratory-gated magnetic resonance imaging to evaluate airway dynamics during tidal breathing in 10 children with obstructive sleep apnea syndrome (OSAS; age, 4.3 ± 2.3 years) and 10 matched control subjects (age, 5.0 ± 2.0 years). We hypothesized that respiratory cycle fluctuations in upper airway cross-sectional area would be larger in children with OSAS. Methods: Studies were performed under sedation. Respiratory gating was performed automatically at 10, 30, 50, 70, and 90% of Inspiratory and expiratory volume. Airway cross-sectional area was measured at four ascending oropharyngeal levels at each increment of the respiratory cycle. Results: We noted the following in subjects with OSAS compared with control subjects: (1) a smaller upper airway cross-sectional area, particularly during inspiration; (2) airway narrowing occurred during inspiration without evidence of complete airway collapse; (3) airway dilatation occurred during expiration, particularly early in the phase; and (4) magnitude of cross-sectional areas fluctuations during tidal breathing noted in OSAS at levels 1 through 4 were 317, 422, 785, and 922%, compared with 19, 1517, and 24% in control subjects (p < 0.001, p < 0.005, p < 0.001, and p < 0.001, respectively). Conclusions: Fluctuations in airway area during tidal breathing are significantly greater in subjects with OSAS compared with control subjects. Resistive pressure loading is a probable explanation, although increased airway compliance may be a contributing factor.
Original language | English (US) |
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Pages (from-to) | 1298-1304 |
Number of pages | 7 |
Journal | American journal of respiratory and critical care medicine |
Volume | 171 |
Issue number | 11 |
DOIs | |
State | Published - Jun 1 2005 |
Externally published | Yes |
Keywords
- Magnetic resonance imaging (MRI)
- Respiratory-gated MRI
- Upper airway
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine