DYNAMIC MAGNETIC-RESONANCE-IMAGING OF VOCAL CORD CLOSURE DURING DEGLUTITION

Background & Aims: Vocal cord closure is instrumental in airway protec tion during deglutition. Conventional imaging of vocal cord closure an d reopening during deglutition requires invasive and nonphysiological methods. The aim of this study was to characterize the biomechanical p roperties of normal vocal cord adduction/abduction during deglutition using echoplanar magnetic resonance imaging, a technique that has the capability of imaging soft-tissue motion with real-time temporal resol ution. Methods: The movements of laryngeal and vocal cord structures d uring swallowing were determined in 11 normal volunteers by single sli ce and axially reformatted multislice coronal echoplanar images. Resul ts: During swallowing, the larynx ascended to peak elevation, maintain ed peak elevation for a discrete interval, and descended to its restin g position. Vocal cord adduction occurred with a symmetric tent-like c onfiguration at the midpoint of maximal laryngeal elevation, whereas v ocal cord abduction occurred at the midpoint of laryngeal descent. Spa tial analysis of vocal cord configuration during adduction determined that the Vocal cords attained an initial parallel configuration during ascent, followed by closure at peak laryngeal elevation. Conclusions: These results show that the vocal cords adduct and abduct synchronous ly with laryngeal ascent and descent, respectively, during deglutition . Echoplanar magnetic resonance imaging constitutes a novel tool used to assess clinical abnormalities of deglutitive laryngeal function.