Real-time MRI of swallowing: intraoral pressure reduction supports larynx elevation.
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 mm3and 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.
Phoniatrics and Pedaudiology, Department of Otorhinolaryngology, University Medical Center, Göttingen, Germany. olthoff@med.uni-goettingen.de.
Arno
A
Olthoff
Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.|DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany.
Arun A
AA
Joseph
Phoniatrics and Pedaudiology, Department of Otorhinolaryngology, University Medical Center, Göttingen, Germany.
Matthias
M
Weidenmüller
Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Blake
B
Riley
Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.|DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany.
Jens
J
Frahm
D000328:Adult; D003199:Computer Systems; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007830:Larynx / Q000033:anatomy & histology / Q000502:physiology*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008365:Manometry / Q000379:methods*; D009055:Mouth / Q000033:anatomy & histology / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D011312:Pressure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014059:Tongue / Q000502:physiology
intraoral pressure; larynx elevation; real-time MRI; swallowing