ARDMS Ultrasound Physics & Instrumentation Practice Exam

The relationship between density and propagation speed in ultrasound is characterized as inversely related. As density increases, the speed of sound in a medium typically decreases, reflecting an important principle in wave propagation. This occurs because sound waves transmit through a medium by interacting with its particles.

In denser materials, particles are more closely packed, which increases the mass that needs to be moved as the sound wave travels. This additional mass results in a slower speed of propagation. Conversely, in less dense media, the particles are not as tightly packed, allowing sound waves to propagate more quickly because there is less mass to move.

Understanding this relationship is crucial for interpreting ultrasound images and optimizing settings for better imaging, as different tissues have varying densities, affecting how ultrasound waves travel through them. Thus, the correct answer highlights this inverse relationship between density and propagation speed.