Figure 1. Anechoic: Structures appear black, meaning no internal echoes. Examples: cysts, vessels, gallbladder ascites, and water. Hypoechoic: Gives off fewer echoes; they are darker than surrounding structures. Example: lymph nodes and tumors. Hyperechoic: Increased density of sound waves compared to surrounding structures. Example: bone and fat calcifications.

Credit: https://onlinelibrary.wiley.com/doi/10.1002/jcu.23542