Multiple swallow test for the quantitative and qualitative evaluation of esophageal motility disorders.

Esophageal motility was evaluated from the analysis of six consecutive swallows. A sum image was generated comprising the representative information of an entire study. Calculation of emptying rates and characterization of the bolus behavior was performed from the sum image and the single swallow data. In 86 patients investigated, liquid and solid-phase studies showed a remarkable variation of single swallow data in normals (relative variation coefficient for liquid: 10%, solid: 14%), which were even higher (p less than 0.001) in patients with disorders (liquid: 31%, solid: 25%). As sum images compensate for this intra-individual variation, false-positive (liquid: 16%, solid: 25%) or negative single swallow findings (liquid: 36%, solid: 27%) are reduced. Qualitative analysis of condensed sum images provided characteristic image patterns representing different pathophysiologic aspects. Since the method introduced better discriminates between normal and pathologic function, it may enhance diagnostic accuracy.