Research Article

On the Physiology of Normal Swallowing as Revealed by Magnetic Resonance Imaging in Real Time

Table 1

Swallowing events revealed by real-time MRI and videofluoroscopy.

Deglutition events Real-time MRIVideofluoroscopy [3]

Valve function
 Oro-velar opening (OOT*, reference)Full rise of soft palate from dorsumNot defined
 Velar-pharyngeal closure (VCT)Contact of soft palate and pharyngeal wallVelopharyngeal sphincter (valve 3)
 Glottal closure (GCT)Closure of glottis and supraglottisLarynx: vocal folds (valve 4c)
 Epiglottic retroflexion (ERT)Contact of epiglottis and supraglottisLarynx: epiglottis and arytenoid to base of epiglottis (valve 4a/b)
 Esophageal opening (EOT)Separation of postcricoid and pharyngeal wallCricopharyngeal sphincter (valve 6)
Bolus transport
 Oro-velar transit (OTT)Oral transit
s: OOTs  s: initiation of tongue movement 
e: OOTe e: bolus head reaches the cross of mandible and tongue base
 Pharyngeal delay (PDT)s: OTTs (OOTs)s: bolus head reaches cross of mandible and tongue base 
e: PTTse: start of laryngeal ascent
 Pharyngeal transit (PTT)s: bolus head passes oro-velar valve s: start of laryngeal ascent 
e: bolus tail passes esophageal sphinctere: bolus tail passes cricopharyngeal region
Other
 Laryngeal ascent (LAT)Ascendance of larynxUpward and forward movement of hyoid and larynx
 Laryngeal descent (LDT)Descendance of larynxNot defined
 Vallecula and piriform sinus filling (SFT)Bolus filling vallecula and piriform sinusNot observed
 Pharyngeal constriction (PCT)Progressive contraction of pharyngeal constrictorTongue base and pharyngeal wall (valve 5). Not observed [3]