70. ULTRASOUNDS: ULTRASOUND TISSUE INTERACTIONS Flashcards
1
Q
- What is the Transducer for sound?
A
- this converts electrical energy into sound energy
- it also converts sound energy into electrical energy
2
Q
- What happens when the Sound Waves enter the body?
A
- they are reflected
3
Q
- What is Scatter?
A
- it refers to the propagation of the Incident sound
waves - these waves are reflected in oblique directions
4
Q
- What happens when Sound Waves interact with rough surfaces?
A
- they are reflected in different directions
5
Q
- What is Reflection in an Ultrasound?
A
- it is the return of the sound wave energy
- this energy goes back to the Transducer
6
Q
- What do we want ideally from the region that is being X-Rayed?
A
- we want many reflections
7
Q
- What is Refraction?
A
- this is when the incident sound wave contacts the
boundary of tissues at an oblique angle
8
Q
- What is Attenuation?
A
- this is the progressive reduction in the intensity of the
wave
9
Q
- Why is the Attenuation of Sound energy clinically important?
A
- it affects the depth of penetration into the tissues
10
Q
- What does an increase of Attenuation lead to?
A
- it leads to a decrease in the intensity of the wave
- this happens as the ultrasound goes deeper into the
body - there is an increase in the ultrasound frequency
11
Q
- What does the Attenuation govern?
A
- it governs the Transducer Selection
- it governs the Operator-controlled Instrument Settings
12
Q
- What 3 factors combine together to form Attenuation?
A
- Absorption
- Scattering
- Reflection
13
Q
- What is Attenuation directly proportional to?
A
- the distance that the ultrasound travels
- the ultrasound frequency
14
Q
- What characteristics effect the Attenuation?
A
THE CHARACTERISTICS OF THE MEDIUM:
- Distance
- Frequency
- Type of medium
15
Q
- What effect does the Distance have on the Attenuation?
A
THE ATTENUATION INCREASES:
- as the ultrasound propagates deeper into the body
