ABSTRACT
Although obstructive sleep apnea is a major public health problem affecting at least 2-4% of the middle-aged population, the pathogenesis of this disorder is poorly understood. Upper airway imaging studies have provided insights into the biomechanical basis for obstructive sleep apnea and the mechanisms underlying the efficacy of various therapeutic interventions for this disorder [i.e., continuous positive airway pressure (CPAP), weight loss, oral appliances, and surgery]. High-resolution anatomical information can be obtained on static and dynamic changes in upper airway dimensions and surrounding soft tissue structures with magnetic resonance imaging (MRI) and computed tomography (CT). Magnetic resonance volumetric three-dimensional reconstructions of the airway and surrounding soft tissue structures are being utilized to accurately quantify anatomical structural risk factors in patients with obstructive sleep apnea. Such imaging studies have allowed us to study the effects of obesity and gender on upper airway structure and function. Upper airway imaging studies have highlighted the singular importance of thickening of the lateral pharyngeal walls in mediating upper airway narrowing during wakefulness and sleep in normals and patients with sleep apnea. Although obstructive sleep apnea involves both an anatomical and neurological component (discussed in other chapters in this volume), we will primarily focus on the anatomical component in this chapter.
