Absorption in ultrasound is directly related to which of the following factors?

Absorption in ultrasound is closely related to frequency. As the frequency of the ultrasound waves increases, the absorption in the medium also typically increases. Higher frequency waves tend to be absorbed more than lower frequency waves due to their shorter wavelengths. This increased absorption occurs because higher frequency waves are more likely to interact with the molecules of the medium, causing them to vibrate more and convert sound energy into heat.

Understanding this relationship is crucial in clinical practice because it influences the choice of frequency for imaging. While higher frequency can provide better resolution, it also means greater absorption, which can limit penetration depth in thicker or denser tissues. Thus, choosing the appropriate frequency is a vital consideration for effective ultrasound imaging.

In contrast, distance, intensity, and phase are not direct factors affecting absorption in the same way frequency does. Distance can influence the overall intensity of the ultrasound beam as it propagates through the medium, but it doesn't determine the absorption itself. Intensity relates to the amplitude of the ultrasound wave but does not directly correlate with how much of that energy is absorbed by the tissue. Lastly, phase refers to the stage of the waveform cycles but has no bearing on absorption characteristics.