What occurs when ultrasound energy is converted into heat within tissue?

When ultrasound energy is converted into heat within tissue, this process is known as absorption. Absorption refers to the phenomenon where the sound waves penetrate the tissue and are transformed into thermal energy, increasing the temperature of the tissue. This is a critical concept in sonography, as it highlights how ultrasound can produce therapeutic effects in addition to diagnostic imaging.

In the context of medical ultrasound, absorption is influenced by several factors, including the frequency of the ultrasound waves and the properties of the tissue. Higher frequency waves tend to be absorbed more readily than lower frequency waves, leading to greater thermal effects in superficial tissues. Understanding absorption is vital for managing potential risks of thermal injury during ultrasound procedures, ensuring that exposure levels remain safe.

In contrast, other processes such as reflection, refraction, and transmission do not involve the conversion of ultrasound energy into heat. Reflection pertains to the bouncing back of ultrasound waves when they hit a different medium, refraction involves the bending of ultrasound waves as they pass through tissues with different acoustic impedances, and transmission relates to the ultrasound waves passing through tissues without being absorbed or reflected significantly. These concepts are fundamental to understanding ultrasound imaging but do not directly involve heating tissue. Thus, absorption is the key process associated with the conversion of ultrasound energy to heat