[Study on the pharyngeal constriction and function of cricopharyngeal muscle in normal persons using dynamic magnetic resonance imaging].

OBJECTIVE: To investigate the superiority of dynamic magnetic resonance imaging as an assessment method of pharyngeal constriction and cricopharyngeal muscle function, and introduce a new way to measure the pharyngeal constriction ratio, anteroposterior diameter of esophageal entrance and thickness of cricopharyngeal muscle in healthy volunteers.

METHODS: Twenty volunteers who were assessed as normal by fiberoptic endoscopic evaluation of swallowing and videofluoroscopic swallowing study were included in this study. With the use of 3.0T magnetic resonance imaging, Fiesta sequence and Asset technique, the median sagittal plane and intervertebral transverse plane from C1 to C5 were scanned repeatedly. Pharyngeal constriction ratio in the median sagittal and intervertebral transverse plane, anteroposterior diameter of esophageal entrance and thickness of cricopharyngeal muscle were assessed and the data were analysed by SPSS13.0.

RESULTS: The intervertebral transverse plane between C1 and C2 was superior in observation of pharyngeal constriction ratio in the same way that the plane between C4 and C5 was superior in cricopharyngeal evaluation. The average of sagittal and intervertebral pharyngeal constriction ratio were estimated as 0.08±0.02, 0.09±0.04 respectively and the average of thickness of cricopharyngeal muscle and anteroposterior diameter of esophageal entrance were (6.50±1.69) mm, (1.99±0.76) mm respectively.

CONCLUSION: Dynamic magnetic resonance imaging was superior in assessing the function of pharyngeal constriction and cricopharyngeal muscle by scanning the swallowing process in the median sagittal and intervertebral transverse plane.