Shadowing

  • a hypoechoic region appearing beneath a structure with abnormally high attenuation

Figure source

Reverberation

  • caused by the ultrasound wave bouncing repeatedly between two strong reflectors, creating multiple, equally spaced, hyperechoic lines that can obscure the true anatomy
  • frequently seen when the ultrasound encounters interfaces like the pleura, metallic objects, or implants
  • can make these structures appear thicker and deeper than they actually are
  • appears as a series of parallel, bright lines that are equally spaced behind the reflective surface

Figure source