Isoechoic describes structures that have the same reflective properties as surrounding tissue.

Isoechoic describes structures that have the same reflective properties as surrounding tissue.

• A. Higher reflectivity than surrounding tissue
• B. No reflection
• C. The same reflective properties as surrounding tissue
• D. Greater attenuation than surrounding tissue

Answer: (C)

In ultrasound imaging, brightness on the screen reflects how much sound is echoed back by tissue, which depends on differences in acoustic impedance. When a structure has the same reflectivity as the surrounding tissue, it produces echoes similar to its neighbors and thus appears with the same shade as the surrounding area. That is isoechoic. Because the echoes are similar, the structure blends in and its borders are hard to distinguish. If something reflected more sound than its surroundings, it would look brighter (hyperechoic). If it reflected less or produced almost no echoes, it would appear darker or completely black (anechoic). Greater attenuation describes how the signal weakens as it travels through tissue, which can cause shadowing behind a structure, but it’s about signal loss with depth rather than having identical reflectivity to nearby tissue.

In ultrasound imaging, brightness on the screen reflects how much sound is echoed back by tissue, which depends on differences in acoustic impedance. When a structure has the same reflectivity as the surrounding tissue, it produces echoes similar to its neighbors and thus appears with the same shade as the surrounding area. That is isoechoic. Because the echoes are similar, the structure blends in and its borders are hard to distinguish.

If something reflected more sound than its surroundings, it would look brighter (hyperechoic). If it reflected less or produced almost no echoes, it would appear darker or completely black (anechoic). Greater attenuation describes how the signal weakens as it travels through tissue, which can cause shadowing behind a structure, but it’s about signal loss with depth rather than having identical reflectivity to nearby tissue.