ARDMS Ultrasound Physics & Instrumentation Practice Exam

How is pressure typically expressed in ultrasound physics?

1. Atmospheres

2. Pascals

3. Hectopascals

4. Millimeters of mercury

The correct answer is: Pascals

In ultrasound physics, pressure is typically expressed in Pascals. This unit, named after Blaise Pascal, measures pressure as force per unit area and is a standard SI (International System of Units) measurement. The Pascal is widely used in many scientific fields, including ultrasound, because it provides a clear and universal way to quantify pressure levels generated in ultrasound waves, especially when discussing parameters like acoustic pressure and sound propagation in different media. While the other units are indeed related to pressure, they are less commonly employed in the context of ultrasound. For instance, atmospheres may be relevant in certain environments or applications, particularly in underwater or aviation-related studies, but they do not provide the granularity needed for typical ultrasound measurements. Hectopascals and millimeters of mercury are also valid pressure units, but Pascals remain the most relevant and frequently used measurement in the context of ultrasound physics due to its compatibility with other SI units and the need for precision in sound wave interactions.