RT Journal Article SR Electronic T1 Functional imaging using computational fluid dynamics to assess effect of stimulation of the hypoglossal nerve on upper airway morphology: A pilot study JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1423 VO 38 IS Suppl 55 A1 Jan De Backer A1 Wim Vos A1 Quan Ni A1 Olivier Vanderveken A1 Paul Parizel A1 Paul Van De Heyning A1 Wilfried De Backer YR 2011 UL http://erj.ersjournals.com/content/38/Suppl_55/1423.abstract AB This study assessed the in-vivo effect of stimulation of the hypoglossal nerve on the upper airway morphology using imaging techniques in combination with computational fluid dynamics (CFD) tools. In 8 patients the upper airway was imaged using CT before and during stimulation of the hypoglossal nerve. Changes in airway volume and resistance were determined using segmentation and CFD. A statistically significant (p = 0.035) enlargement of the volume for the upper airway at the level of the tongue-base was observed. A significant correlation (R2= 0.89, p=0.002) was found between the change in hydraulic radius and the volume changes at the level of the palate. The distance from the tongue base to the mandibula measured just above the epiglottis correlated significantly with the change in upper airway resistance (R2=0.91, p=0.014).It could be concluded that stimulating the hypoglossal nerve changes the upper airway morphology. A relatively complex motion of the tongue is observed with an enlargement of the airway lumen predominantly near the tongue base. Depending on the volume of the oral cavity, the enlargement is homogeneous or a decrease in cross sectional area occurs at the palatal level. The distance between the tongue base and the mandibula appears to be a good surrogate for changes in upper airway resistance.