Dynamic magnetic resonance imaging of swallowing and laryngeal motion using parallel imaging at 3 T.
OBJECTIVE
To evaluate the feasibility of an optimized MRI protocol based on high field imaging at 3 T in combination with accelerated data acquisition by parallel imaging for the analysis of oropharyngeal and laryngeal function.


METHODS
Fast 2D gradient echo (GRE) MRI with different spatial resolutions (1.7x2.7 and 1.1x1.5 mm2) and image update rates (4 and 10 frames per second) was employed to assess pharyngeal movements and visualize swallowing via tracking of an oral contrast bolus (blueberry juice). In a study with 10 normal volunteers, image quality was semi-quantitatively graded by three independent observers with respect to the delineation of anatomical detail and depiction of oropharynx and larynx function. Additionally, the feasibility of the technique for the visualization of pathological pre- and post-surgical oropharynx and larynx function was evaluated in a patient with inspiratory stridor.


RESULTS
Image grading demonstrated the feasibility of dynamic MRI for the assessment of normal oropharynx and larynx anatomy and function. Superior image quality (P<.05) was found for data acquisition with four frames per second and higher spatial resolution. In the patient, dynamic MRI detected pathological hypermobility of the epiglottis resulting in airway obstruction. Additional post-surgical MRI for one clinical case revealed morphological changes of the epiglottis and improved function, i.e., absence of airway obstruction and normal swallowing.


CONCLUSIONS
Results of the volunteer study demonstrated the feasibility of dynamic MRI at 3 T for the visualization of the oropharynx and larynx function during breathing, movements of the tongue and swallowing. Future studies are necessary to evaluate its clinical value compared to existing modalities based on endoscopy or radiographic techniques.
Breyer
Tobias
T
Section of Neuroradiology, Freiburg Institute of Musicians Medicine, Department of Otorhinolaryngology, University of Freiburg, 79106 Freiburg, Germany.
Echternach
Matthias
M
Arndt
Susan
S
Richter
Bernhard
B
Speck
Oliver
O
Schumacher
Martin
M
Markl
Michael
M
D000328:Adult; D003287:Contrast Media; D003679:Deglutition / Q000502:physiology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007830:Larynx / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009038:Motion; D012135:Respiratory Sounds / Q000503:physiopathology
D003287:Contrast Media