What term describes the hyperechoic region seen beneath a complex structure due to decreased attenuation?

What term describes the hyperechoic region seen beneath a complex structure due to decreased attenuation?

• A. Acoustic Shadowing
• B. Acoustic Enhancement
• C. Reverberation
• D. Refraction

Answer: (B)

Posterior acoustic enhancement occurs when a structure attenuates ultrasound waves less than surrounding tissues. Because more sound passes through the structure with less energy loss, the tissue behind it reflects stronger echoes, making that region appear brighter (hyperechoic) on the image. This is commonly seen behind fluid-filled or low-attenuation areas, like cysts, where the posterior region looks enhanced due to the decreased attenuation in front of it. In contrast, acoustic shadowing produces a dark area behind a highly attenuating object, reverberation creates multiple echo lines, and refraction causes beam bending and artifact displacement—none of which explain a bright area behind the structure.

Posterior acoustic enhancement occurs when a structure attenuates ultrasound waves less than surrounding tissues. Because more sound passes through the structure with less energy loss, the tissue behind it reflects stronger echoes, making that region appear brighter (hyperechoic) on the image. This is commonly seen behind fluid-filled or low-attenuation areas, like cysts, where the posterior region looks enhanced due to the decreased attenuation in front of it. In contrast, acoustic shadowing produces a dark area behind a highly attenuating object, reverberation creates multiple echo lines, and refraction causes beam bending and artifact displacement—none of which explain a bright area behind the structure.