Which property of sound waves allows them to visualize internal organs and tissues during ultrasound imaging?

The property of sound waves that allows for the visualization of internal organs and tissues during ultrasound imaging is echo reflection. In ultrasound imaging, high-frequency sound waves (typically above 20,000 Hz) are transmitted into the body. When these waves encounter different tissues or interfaces, they are partially reflected back to the ultrasound transducer.

The intensity and timing of these echoes provide crucial information about the structure and composition of the tissues they have interacted with. This echo reflection is processed to create images that represent the internal anatomy, revealing size, shape, and any potential abnormalities within the organs.

While frequencies greater than 20,000 Hz are indeed characteristic of ultrasound, echo reflection is the specific mechanism by which imaging occurs, making it essential for the effective use of ultrasound as a diagnostic tool. This process allows healthcare professionals to visualize and assess internal organs non-invasively.

The other options, such as amplitude modulation and phase differences, do not play a direct role in the fundamental imaging process of ultrasound.