What is the order of attenuation from lowest to highest?

Attenuation refers to the reduction of the amplitude and intensity of ultrasound waves as they pass through different tissue types. The correct order of attenuation from lowest to highest is based on the varying acoustic properties of these tissues.

Air has the lowest attenuation. It does not conduct ultrasound well, leading to significant reflection and scattering of sound waves, but it allows them to travel easily without significant absorption.

Fat follows air in terms of lower attenuation. Fat has a relatively low density and provides some resistance to sound wave propagation but is considerably less attenuating than denser tissues.

Muscle has a higher attenuation than fat. It has a higher density and a greater capacity to absorb ultrasound energy, which means that sound waves are more significantly reduced as they travel through muscle compared to fat.

Finally, bone exhibits the highest attenuation. Bone is very dense and is composed of tightly packed minerals, which strongly absorb and reflect ultrasound waves, leading to the highest level of attenuation among typical biological tissues.

This understanding of tissue attenuation is crucial for ultrasound imaging, as it impacts the quality and depth of image formation.