Measuring Vallecular Volume on Flexible Endoscopic Evaluation of Swallowing: A Proof of Concept Study

Currently, no method exists to measure the size of pharyngeal and laryngeal structures on endoscopy. Imaging for dysphagia diagnostic techniques, for the most part, still relies on qualitative assumptions and cursory visual examinations to induce patients’ swallowing safety and function. In this proof of concept study, we measured vallecular cavity volume using simultaneous modified barium swallows (MBS) and flexible endoscopic evaluation of swallowing (FEES). Similar to the three-dimensional image compilation fields of facial reconstruction, medical imagery, and forensic science, this proposed methodology combines the two-dimensional images yielded in FEES and MBS videos to calculate estimates of the valleculae in a 3D perspective. A tracking tool was used to measure distances on MBS, while endoscopic specifications were used to find distances on FEES. This combination of ratio measurements allowed for measurement on both the MBS and FEES. In a sample of n = 37 dysphagia patients referred for MBS/FEES studies, the mean distance from the tip of endoscope to the closest point of epiglottis was 25.38 mm, the mean vallecular area outlined on MBS video was 84.72 mm², the mean epiglottal width was 18.16 mm, and the mean vallecular volume was 1.55 mL. Future application could include tracking growth of tumors, glottic opening, volume of residue and tracking of any other important outcome involving movement, size, and targets of interest with higher precision.