Which of the following conditions creates more attenuation?

Attenuation refers to the decrease in intensity of ultrasound as it travels through a medium. Several factors influence attenuation, including distance, frequency, and the properties of the medium.

In scenarios involving longer distances, ultrasound waves travel through a greater volume of tissue, which results in more energy loss due to absorption and scattering. Therefore, deeper distances contribute to higher attenuation.

Higher frequencies are also associated with greater attenuation because higher-frequency ultrasound waves interact more with tissue and therefore dissipate energy more quickly compared to lower frequencies. This is due to the increased interaction of sound waves with the microscopic structures of the medium, which leads to more energy loss through absorption.

Combining deeper distances with higher frequencies leads to the most pronounced attenuation effect, because both factors contribute to the energy loss of the ultrasound waves. Thus, deeper distances compound the attenuation caused by the higher frequency, resulting in significant overall attenuation of the ultrasound signal as it travels through the tissue.