Development and Clinical Implementation of Voice-, Probe-, Neck Movement-Synchronized Functional Laryngeal...

To introduce a novel system called voice-, probe-, neck movement-synchronized functional laryngeal ultrasonography (VPN-FLUS) that integrates ultrasound images with patient and examiner voice recordings, real-time probe manipulation videos, and visual inspection of the neck, thus overcoming the limitations of conventional laryngeal ultrasonography that suffers from low reproducibility.

Examinations were performed using the Canon Aplio i700 ultrasound system with linear probes (4.5-13 MHz or 2.8-9 MHz). Audio was recorded using a nondirectional electret condenser microphone (100-10,000 Hz). The microphone signal and ultrasound images were simultaneously captured on a laptop via Open Broadcaster Software Studio, with an additional recording that documented the session with the patient on a mobile phone. All video and audio data were synchronized post-examination using Shotcut. Between March 2025 and February 2026, 53VPN-FLUS examinations were performed, including 12 healthy volunteers and 38 outpatients with voice disorders.

VPN-FLUS enabled continuous and dynamic visualization of the larynx, facilitating precise identification of the intrinsic laryngeal muscles and their spatial interrelationships. Visualization of each intrinsic laryngeal muscle's attachment sites to the arytenoid cartilage (AC) made it possible to depict the rotating, rocking, gliding/sliding, and reverse rocking movements of the ACs as well as assess various natural phonatory conditions, including pitch variations, and differentiation between respiratory and phonatory states. Aside from cervical dynamics, the system also enabled observation of overall laryngeal movement.

VPN-FLUS technology overcomes several limitations of conventional laryngeal ultrasonography and provides comprehensive and reproducible imaging of the larynx. This technique enables more detailed anatomical understanding, allows multidimensional assessment of the larynx in its physiological state, and provides reproducible imaging of the larynx. Further clinical validation with more cases is required to establish its clinical utility.