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

Abstract

AbstractThis 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 ApplicationsUltrasonography, 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.