Question

Concerning the reflection of ultrasound waves:

a. Specular reflection occurs when the size of the reflector is much larger than the ultrasound wavelength

b. The angle of specular reflection depends on the differences in acoustic impedance of tissues forming the boundary and is described by Snell’* law

c. For a normal angle of incidence, approximately 30–40% of ultrasound is transmitted at an interface between bone and soft tissue

d. The degree of ultrasound reflection at an interface between different soft tissues (for example, ***–muscle interface) is up to 10%

e. The echo texture of the liver parenchyma is due to scattering

Answer 1

a. True.

b. False. The angle of specular reflection is, by definition, equal to the angle of incidence. Snell’* law governs the process of refraction.

c. False. Approximately 30–40% is reflected, and 60–70% is transmitted.

d. False. Only up to 1–2% is reflected.

e. True. Hence, the echo texture of the liver is independent of the sonication angle.