Real‐time MRI of swallowing: intraoral pressure reduction supports larynx elevation. (30th September 2016)

• Record Type: Journal Article
• Authors: Olthoff, Arno; Joseph, Arun A.; Weidenmüller, Matthias; Riley, Blake; Frahm, Jens
• Is Part Of: NMR in biomedicine. Volume 29:Number 11(2016:Nov.)
• Page Start: 1618
• Page End: 1623
• Publication Date: 2016-09-30
• Subjects: intraoral pressure -- larynx elevation -- real‐time MRI -- swallowing; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.3621
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : The reduction in intraoral pressure during swallowing has previously been linked to bolus transport, although no such relation has yet been proven. The purpose of this work was to evaluate the time course of intraoral pressure during swallowing using simultaneous real‐time magnetic resonance imaging (MRI) and dynamic pressure recordings. Real‐time MRI based on highly undersampled radial fast low‐angle shot (FLASH) and regularized nonlinear inverse reconstruction was performed at 3 T using a standard head coil and a mid‐sagittal section covering the entire oral cavity. Voluntary swallowing (10 mL of pineapple juice or saliva) was monitored for about 30 s in 11 normal subjects at spatial and temporal resolution of 1.3 × 1.3 × 8 mm 3 and 40 ms, respectively. Simultaneously, the intraoral atmospheric pressure was recorded at a resolution of 10 ms during the entire course of deglutition. Quantitative measures of bolus transport, larynx elevation and submental muscle changes were obtained from the image series. As a key result, negative intraoral pressure accompanied laryngeal elevation during swallowing in all subjects. A reduction in submental muscle length during swallowing was also observed. No correlations of maximum negative pressure with larynx elevation and submental muscle change were found. In conclusion, intraoral pressure reduction during swallowing is not connected to oral bolus transport, but supports laryngeal elevation by palatal fixation of the tongue. Abstract : Simultaneous real‐time magnetic resonance imaging and dynamic pressure recordings were used to study the role of intraoral pressure during voluntary swallowing. As a key result, negative intraoral pressure accompanied laryngeal elevation in all subjects. In contrast with previous suggestions, intraoral pressure reduction during swallowing is not connected to oral bolus transport, but supports laryngeal elevation by palatal fixation of the tongue.