ABSTRACT
I. Introduction 514
II. Normal Upper Airway Anatomy 515
III. Upper Airway Imaging Modalities 516
A. Acoustic Reflection 518
B. Fluoroscopy 518
C. Nasopharyngoscopy 522
D. Cephalometry 522
E. Computed Tomography 523
F. Magnetic Resonance Imaging 524
IV. Upper Airway Imaging Studies Examining the Pathogenesis
of Obstructive Sleep 525
A. “Static” Upper Airway Anatomy 525
B. “Dynamic” Upper Airway Imaging 532
C. State-Dependent Upper Airway Imaging 534
V. Insights into the Treatment of Obstructive Sleep with Upper
Airway Imaging 536
A. Weight Loss 536
B. Continuous Positive Airway Pressure 537
C. Oral Appliances 537
D. Upper Airway Surgery 539
VI. Imaging of the Upper Airway in Children 541
A. Anatomical Evidence for OSAS 542
B. Functional Evidence for OSAS 542
C. Imaging Modalities for the Upper Airway in Children 543
D. MRI for Upper Airway and Surrounding Tissues in
Children 543
E. MRI to Assess Developmental Changes of the Upper
Airway During Childhood 545
F. MRI to Assess the Upper Airway in Children with
Craniofacial and Genetic Disorders 546
VII. Clinical Utility of Upper Airway Imaging 546
VIII. Conclusions 547
Acknowledgments 547
References 547
I. Introduction
Obstructive sleep apnea is a highly prevalent disorder with major public health
ramifications. Upper airway imaging has become a powerful tool to understand
the pathogenesis of this disorder in adults and children. Upper airway imaging
studies have provided important insights into the anatomical basis of obstructive
sleep apnea and the mechanisms by which treatments [continuous positive airway
pressure (CPAP), weight loss, oral appliances, upper airway surgery] for this dis-
order increase upper airway caliber. Upper airway soft tissue and craniofacial
structures can be objectively quantified with imaging techniques. Upper airway
imaging has been utilized to evaluate the effects of gender and obesity on
upper airway structure and function. Three-dimensional volumetric images of
the upper airway have been used to phenotype the upper airway. State-dependent
and dynamic imaging studies have provided important information on the com-
pliance and collapsibility of the upper airway.
