Interactions of UTZ w/ MATTER

Question 1

Loss of acoustic energy w/ distance traveled caused chiefly by scattering and absorption

Answer 1

Attenuation

Question 2

occurs when a sound wave strikes an object larger than the wavelength

Answer 2

Reflection

Question 3

When the beam is L to the tissue boundary

Answer 3

Reflection

Question 4

The change in direction of UTZ is not L to the tissue boundary

Answer 4

Refraction

Question 5

Occurs when the beam encountered an interface b/n 2 different tissue at an OBLIQUE angle

Answer 5

Refraction

Question 6

Misplacement of anatomy

Answer 6

Disadvantage: Refraction

Question 7

Occurs when an ultrasound wave strikes a boundary b/n 2 small structures

Answer 7

Scattering

Question 8

The process whereby acoustic energy is converted to heat energy

Answer 8

Absorption

Question 9

Process whereby the energy is LOST and can’t be recovered

Answer 9

Absorption

Question 10

High frequency = ?

Answer 10

Greater amount of absorption

Question 11

Occurs when the beam travels through tissue and it will diverge due to diffraction effects

Answer 11

Divergence

Question 12

Used b/n the face of the transducer and the skin

Answer 12

Acoustic coupling Gel

Question 13

Line at the periphery of two tissues w/c propagate UTZ differently

Answer 13

Boundaries

Question 14

Factors affecting Echo Signal Amplitude

Answer 14

No. of scatterers per unit volume
acoustic impedance differences at the scatterer’s interface
sizes of the scatterer’s
ultrasonic frequency