A novel protocol for three-dimensional reconstruction of pharyngeal airway on computed tomography

Three-dimensional measurement of the pharyngeal airway has been widely used, but the three-dimensional reconstruction of pharyngeal airway has been performed in various ways, especially during the anterior boundary demarcation of the nasopharyngeal airway and oropharyngeal airway. This would inevitably affect the measurement and lead to noncomparison between different studies. Our study provided a novel method for anterior boundary demarcation of pharyngeal airway that defined the anterior boundary of nasopharyngeal airway as the "choana" according to the anatomical definition and defined the anterior boundary of oropharyngeal airway as a plane perpendicular to the long axis of soft palate and through the intersections of the lateral space and inferior space to soft palate according to the physiologic characteristics of soft palate. By 2-step segmentation, a three-dimensional image of pharyngeal airway was eventually reconstructed.Ten computed tomographic scans of pharyngeal airway were included for the anterior boundary demarcation and three-dimensional reconstruction by a medical imaging software (Surgicase 5.0; Materialise Interactive Medical Image Control System, Leuven, Belgium), with the volume and surface area being calculated. By using intraclass correlation coefficient, the reliability between intra- and interobservers of this method was well tested.The method established in this study for anterior boundary demarcation and three-dimensional reconstruction of pharyngeal airway is highly reliable and could more veritably reflect the intrinsic anatomical characteristics of the pharyngeal airway.