Methodological Procedures to Acquire and Analyze Ultrasound Images of Swallowing: A Scoping Review

This scoping review aimed to identify methodological procedures for acquiring and analyzing ultrasound images related to swallowing in adults and older adults. The inclusion criteria were based on the PCC strategy (participants, concept, and context), as follows: population (adults and older adults), concept (ultrasound assessment), and context (swallowing assessment). The review included observational, experimental, descriptive, and analytical studies and excluded those that were not available in full, animal studies, in vitro studies, letters to the editor, errata, study protocols, and those that used ultrasound for purposes other than swallowing. There were no language and time restrictions. Two independent blinded professionals selected 81 articles that met the inclusion criteria from different databases. The most evaluated parameters included tongue morphology and movements, hyoid bone displacement, swallowing muscle area, and pharyngeal residue detection, such as pharyngeal wall mobility. They used convex and linear transducers (3 MHz to 8 MHz) positioned in the submental, laryngeal, and lateral regions of the neck. The subjects were seated and instructed to eat different food volumes and consistencies. The literature mapping showed that ultrasound is a promising diagnostic tool, helping clinicians understand swallowing disorders, as it provides static and dynamic images in different modes and positions. Also, patients receive real-time biofeedback of changes related to dysphagia.