Detection of Swallowed Bolus Transit in the Adult Cervical Esophagus by Transmission-Mode Ultrasound

This developmental device pilot study compared transmission ultrasound detection of cervical esophageal bolus transit with videofluoroscopy contrast images during barium swallow evaluation. An ultrasound transmitter-receiver pair on the neck recorded contrast swallows compiled into heatmaps in adult patients. Using prespecified criteria for qualifying interpretable studies, a unique pattern of ultrasound heatmap features of signal attenuation hypothesized to indicate bolus transit effects on the ultrasound transmission signal was labeled for later comparison to the videofluoroscopic image frame ranges of swallowed bolus contrast passing between the paired ultrasound sensors anterior to C5-C6 cervical vertebrae. In total, 15 studied patients met the inclusion criteria for interpretable image labeling and quality for ultrasound and corresponding videofluoroscopy recordings for 211 swallows. Ultrasound detection yielded 200 true positives, 16 false positives, and 11 false negatives based on the overlap of ultrasound and videofluoroscopic frame ranges: sensitivity 95% and specificity 92%. Transmission ultrasound bolus detection in the cervical esophagus is feasible.