The Reliability of Classification of Upper Esophageal Imaging Pattern Performed by Examination of Normal Swallowing

Abstract

This study evaluated the reliability of the classification of upper esophageal imaging patterns．This classification is based on examination of healthy subjects using videofluoroscopy in the antero-posterior projection．By laterality of just under pyriform sinus flow，an overall classification of the imaging pattern is made as follows：only left (right) side pyriform sinus flow，dominant left (right) side pyriform sinus flow，or bilateral pyriform sinus flow．The pattern is segmented based on the existence of confluence in the upper esophagus，and 13 types of imaging patterns are defined．There were 52 healthy subjects who swallowed 5ml of 40％ barium solution three times each．The pattern that appeared twice in three swallows was considered “the first pattern”．After a break of one whole day and night，swallowing three times was performed again，and these results were considered “the retest pattern”．The first pattern was compared with the retest pattern．In 49 subjects (94％)，the first pattern was the same as the retest pattern．Even among healthy subjects，differences existed in the function of the pharyngoesophageal segment．However，imaging patterns appeared to be constant for a given individual．Decisions regarding the imaging pattern were made by adopting the pattern that appeared twice in three swallows．However，for a qualitative classification，errors are frequently made in the classification boundary．These findings indicated that the classification of upper esophageal imaging patterns was appropriate．