1 research outputs found
Automated pharyngeal phase detection and bolus localization in videofluoroscopic swallowing study: Killing two birds with one stone?
The videofluoroscopic swallowing study (VFSS) is a gold-standard imaging
technique for assessing swallowing, but analysis and rating of VFSS recordings
is time consuming and requires specialized training and expertise. Researchers
have recently demonstrated that it is possible to automatically detect the
pharyngeal phase of swallowing and to localize the bolus in VFSS recordings via
computer vision, fostering the development of novel techniques for automatic
VFSS analysis. However, training of algorithms to perform these tasks requires
large amounts of annotated data that are seldom available. We demonstrate that
the challenges of pharyngeal phase detection and bolus localization can be
solved together using a single approach. We propose a deep-learning framework
that jointly tackles pharyngeal phase detection and bolus localization in a
weakly-supervised manner, requiring only the initial and final frames of the
pharyngeal phase as ground truth annotations for the training. Our approach
stems from the observation that bolus presence in the pharynx is the most
prominent visual feature upon which to infer whether individual VFSS frames
belong to the pharyngeal phase. We conducted extensive experiments with
multiple convolutional neural networks (CNNs) on a dataset of 1245 bolus-level
clips from 59 healthy subjects. We demonstrated that the pharyngeal phase can
be detected with an F1-score higher than 0.9. Moreover, by processing the class
activation maps of the CNNs, we were able to localize the bolus with promising
results, obtaining correlations with ground truth trajectories higher than 0.9,
without any manual annotations of bolus location used for training purposes.
Once validated on a larger sample of participants with swallowing disorders,
our framework will pave the way for the development of intelligent tools for
VFSS analysis to support clinicians in swallowing assessment