The videofluoroscopic swallowing study has been considered a gold standard assessment tool for oral-pharyngeal dysphagia for decades. However, swallowing biomechanics are complex, and the absence of sophisticated image processing tools has made it difficult to quantitatively analyze fluoroscopic studies.
As a result, the full potential of VFS Studies has generally not been realized. The primary means of interpretation has been through subjective impressions. Though invaluable for some purposes, such as documenting aspiration or penetration, subjective determination of mechanical events is problematic, and can lead to poor reliability across raters.
WHAT IS SWALLOWTAIL?
Swallowtail is a state-of-the-art software application with a number of integrated tools designed to allow sophisticated and powerful quantitative analysis of VFS Studies.
The Swallowtail measurement methodology is easy to learn, easy to perform, fast and yields reproducible results.
Swallowtail is based on the quantitative measurement methodology developed by Dr. Rebecca Leonard and Dr. Katherine Kendall at the University of California, Davis. However, the program is not limited to their methods. Swallowtail tools can be used to make a wide variety of linear, area and temporal measures that may be of interest to, or developed by, clinicians and researchers.
With the inclusion of quantitative assessment to their fluoroscopic analyses, Leonard and Kendall hoped to reduce their dependence on subjective impressions, which often failed to achieve agreement among members of their Dysphagia Team. In addition, they felt it would force them to focus on the specific gestures responsible for bolus movement, as well as on bolus movement itself, which is more easily visualized due to contrast-enhancement. Finally, they felt obligated to maximize the potential of the fluoroscopic study, which exposes patients to ionizing radiation. Over time, this approach has proved to be extremely valuable for both clinical and research purposes. A particular goal for Swallowtail has been to retain clinician/investigator judgment in determining critical locations of significant swallowing events, while making the actual measurement of these events as facile, and automatic, as possible.
The straightforward user interface enables the practitioner to take and store the multitude of measurements described above. On-screen controls allow adjustments to video brightness and contrast, as well as playback features like roll forward, reverse and stop action. These and other convenient features give Swallowtail a dramatic edge over manual objective measurement methods and make detailed, accurate analysis a reality.