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Gastrointestinal tract and salivary glands
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Same positioning as Fig. 5.15a with the beam collimated to include the front of the face and all pharyngeal structures. While close collimation reduces image flair and patient dose, it is important not to collimate too closely as swallowing is a dynamic process and an unsteady patient may move slightly during the swallow. A lateral VFSS section image is shown demonstrating the pharyngeal stage of the swallow (Fig. 5.19a). Contrast agent is seen pooling within the pharyngeal spaces rather than flowing through to the oesophagus. The epiglottis cartilage has not sealed off the laryngeal inlet, and contrast agent is seen trickling down the anterior trachea. This is known as aspiration.
Airflow through the supraglottis during inspiration
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
L. Reid, M. Hayatdavoodi, S. Majumdar
The presentation of EILO typically occurs in the supraglottic region, but closure at the glottis, or a combination of both has been documented (Nielsen et al. 2013; Walsted et al. 2021). Supraglottic collapse during EILO involves the anteromedial movement of the arytenoid cartilages and overlying mucosa with their associated corniculate cartilages, including the posterior aspect of the aryepiglottic folds. The supraglottis is defined as the upper region of the larynx situated between the laryngeal inlet and the glottis. The mechanism behind supraglottic collapse is largely unknown but several hypotheses have been proposed. Halvorsen et al. (2017) published a statement on behalf of the European Respiratory Society and European Laryngological Society which outlines three pathophysiological mechanisms of inducible laryngeal obstruction, with mechanical insufficiency being implicated in the supraglottic obstruction observed during exercise. This hypothesis suggests that laryngeal tissue is unable to withstand forces induced by inspiratory airflow.
Improvements resulting from respiratory-swallow phase training visualized in patient-specific computational analysis of swallowing mechanics
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2018
Thi Tu Anh Tran, Bonnie Martin Harris, William G. Pearson
As the bolus enters the hypopharynx, the rapid elevation of the hyolaryngeal complex marks the onset of the pharyngeal phase of swallowing. The suprahyoid muscles (mylohyoid, geniohyoid, stylohyoid and digastric) displace the hyoid anterosuperiorly, translating force through the thyrohyoid membrane and muscle to assist in elevating the larynx. The stylopharyngeus, attached to the posterior thyroid cartilage, further facilitates laryngeal elevation. The palatopharyngeus and salpingopharyngeus work together to shorten the pharynx and to elevate the larynx (Figure 1). The suprahyoid muscles and the long pharyngeal muscles (stylopharyngeus, palatopharyngeus and salpingopharyngeus) all displace the hyolaryngeal complex comprised of hyoid bone, larynx and associated structures, including the trachea and cricopharyngeus muscle that forms the pharyngoesophageal segment (PES). The net movement of the hyolaryngeal complex displaces the laryngeal inlet of the upper airway from the trajectory of an oncoming bolus contemporaneous with laryngeal vestibular closure resulting from approximation of the arytenoid cartilages to the petiole of the epiglottis and epiglottic inversion (Logemann et al. 1992). Vocal fold adduction is the final mechanism to protect the airway. Prior to laryngeal elevation and pharyngeal shortening and associated pharyngoesophageal segment opening, the cricopharyngeus muscle relaxes and further facilitates PES opening. After the bolus enters the PES, pharyngeal constrictors clear the remaining bolus through the PES thus completing the pharyngeal phase of swallowing.
Modelling of swallowing organs and its validation using Swallow Vision®, a numerical swallowing simulator
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2019
Yukihiro Michiwaki, Tetsu Kamiya, Takahiro Kikuchi, Yoshio Toyama, Keigo Hanyuu, Megumi Takai, Seiichi Koshizuka
The swallowing movement begins with the motion of the tongue for transporting the bolus and the elevation of the soft palate. Subsequently, the hyoid bone, thyroid cartilage and cricoid cartilage are raised forward and upward, and the pharyngeal wall contracts and shortens. Gradually, the epiglottis inverts downward and the arytenoids move inward and forward, closing the laryngeal inlet. Within the larynx, the vocal cords move inwardly, touch each other and close the glottis. Finally, the inlet of the oesophagus opens, and the bolus is passed into the oesophagus (Figure 5). Such movements were reproduced with the organ model.