What ultrasound term describes a structure that appears slightly darker than surrounding tissue, yielding a weaker image?

What ultrasound term describes a structure that appears slightly darker than surrounding tissue, yielding a weaker image?

• A. Hypoechoic
• B. Anechoic
• C. Artifacts
• D. Anisotropy

Answer: (A)

On ultrasound, tissues are described by echogenicity—their brightness relative to surrounding structures. A structure that appears slightly darker than its neighbors has lower echogenicity, which is called hypoechoic. Fewer echoes return from it, so the image is weaker and the area looks darker, though not completely black. By contrast, anechoic structures are entirely black because they produce no internal echoes (fluid-filled spaces). Anisotropy is when echogenicity changes with the angle of the probe, and artifacts are imaging distortions not representing real anatomy. So the term that best fits a structure that’s darker and yields a weaker image is hypoechoic.

On ultrasound, tissues are described by echogenicity—their brightness relative to surrounding structures. A structure that appears slightly darker than its neighbors has lower echogenicity, which is called hypoechoic. Fewer echoes return from it, so the image is weaker and the area looks darker, though not completely black. By contrast, anechoic structures are entirely black because they produce no internal echoes (fluid-filled spaces). Anisotropy is when echogenicity changes with the angle of the probe, and artifacts are imaging distortions not representing real anatomy. So the term that best fits a structure that’s darker and yields a weaker image is hypoechoic.