Ultrasound Pulsed Wave Doppler Imaging of the Esophagus Illustrates the Effects of Water Volume on Bolus Kinematics

Abstract

This study aimed to elucidate the effects of water volume on flow properties of bolus (passage time and velocities) at the esophagus orifice using ultrasonic pulsed wave Doppler method. Five healthy males and five females were asked to consume 3, 6, 9 and 12 mL water in a single swallow. An ultrasound probe was placed against each subject's neck to observe the flow properties of bolus. The velocity spectra of the bolus at the esophagus orifice were analyzed. Our results revealed that velocity of bolus was easily affected by volume of water, and the passage time and velocities increased as the increase in volume. Practical Applications Ultrasonography, using a medical ultrasound instrument, is an effective method for observing bolus kinematics during swallowing. The velocity spectra of bolus can be visualized for different volume of water using the pulsed wave Doppler method. When a bolus of food is swallowed, aspiration that the bolus partly enters the trachea instead of the esophagus may occur. Water is known to show a high possibility of aspiration. This study revealed that reducing volume of water decreases the passage time and velocities of bolus at the esophageal entrance. Therefore, this technique can be used for designing the texture of food materials for people who experience aspiration or suffocation by food.

A Pilot Study on Ultrasound Elastography for Evaluation of Mechanical Characteristics and Oral Strategy of Gels

“…In addition, the image signals demonstrate strong contrast that easily differentiates the tongue from its neighboring structures; therefore, ultrasonography B (bright) mode or M (motion) mode has been widely used in many studies of the tongue (Stone and Shawker 1986;Peng et al 1995Peng et al , 2000Peng et al , 2007Watkin 1998;Blissett et al 2007;Gao et al 2012Gao et al , 2013. The velocity spectrum of bolus flow in the pharynx has recently been determined by the ultrasonic pulse Doppler method (Hasegawa et al 2005;Kumagai et al 2009;Gao and Kohyama 2014).…”

Simultaneous X-ray Video-Fluoroscopy and Pulsed Ultrasound Velocimetry Analyses of the Pharyngeal Phase of Swallowing of Boluses with Different Rheological Properties

“…The extensional viscosities of the thickened solutions were determined using the Hyperbolic Contraction Flow (HCF) system mounted on an Instron 5542 (Instron Corp., Canton, USA). The HCF method is described in detail elsewhere [ 19 – 21 ].…”

“…Water, which often causes aspiration during swallowing, travelled with a velocity of 0.5 m/s, while the velocity of yoghurt during pharyngeal transport was recorded as 0.2 m/s. Similarly, Gao and Kohyama [ 19 ] used the UVP technique to examine the influence of water volume on bolus kinematics. In that study, they concluded that reducing the volume of the water caused the passage time and the bolus velocity in the oesophagus to decrease.…”

Supporting young researchers in food texture studies

“…Ultrasound imaging is a safe and noninvasive method that can be used to observe tongue movements during the oral processing and swallowing of soft foods (Gao et al, ; Gao & Kohyama, ). A commercially available, acoustic coupling polymer gel can also be used as an artificial tongue (Gao, Ishihara, et al, ; Gao, Nakao, Ishihara, Funami, & Kohyama, ).…”