Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ultrasound Physics > Chapters 9-11 Final > Flashcards

Chapters 9-11 Final Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What is another name for the near field?

a. focal zone
b. far field
c. Fresnel zone
d. Fraunhofer zone

A

Fresnel Zone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

True or False

The focal point is the region around the focus where the beam is relatively narrow?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The sound beam exits the probe and immediately enters the __________ zone.

A

Fresnel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The diameter of the active element is 16mm, and the near zone length is 10cm. The focal zone is 6cm long. Based on this information answer the following questions:

  1. What is the best estimate of the diameter or width of the sound beam as it exits the transducer?
  2. What is the diameter of the sound beam at a depth of 10cm?
  3. At what depth is the focus?
  4. At which of the following depths is the beam widening?
A
  1. 16mm
  2. 8mm
  3. 10cm
  4. 11.64cm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following terms does not belong?

a. focus
b. end of the near zone
c. Fraunhofer
d. focal point

A

Fraunhofer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

True or False

The sonographer can change the location of the focus with modern ultrasound systems.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Transducer diameter and focal depth are directly or inversely related?

A

directly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Frequency and focal depth are directly or inversely related?

A

directly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The smaller diameter PZT beam will create?

A

lower frequency and shallow focus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The larger diameter PZT beam will create?

A

higher frequency and deep focus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A pair of 8MHz probes are identical except for the element diameter. The active element diameters are 6mm and 12mm, respectively. The sound beam of which probe will have a shallower focus?

A

6mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Crystal diameter and beam divergence are directly or inversely related?

A

inversely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which size crystals will improve lateral resolution in the far field? (large or small)

A

large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Small sound sources that create V-shaped beams that are inconsistent between large and small is a principle called the ___________ principle.

A

Huygens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or False

Small transducer diameters produce a beam with less divergence.

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

True or False

High frequency beams will produce less divergence.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which of the following probes creates a beam with the most divergence?

a. 4mm diameter, 4MHz
b. 6mm diameter, 8MHz
c. 4mm diameter, 2MHz
d. 5mm diameter, 8MHz

A

4mm diameter, 2MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Lateral resolution is best at the?

A

focus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Does Axial resolution change?

Yes or No

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Lateral resolution is improved in the far field the best with?

A

higher frequency sound beams

21
Q

True or false

The sonographer can adjust the internal focusing.

A

False

22
Q

When a beam becomes focused, it?

A

has a focal zone that gets smaller

23
Q

True or False

The diameter of the ceramic and frequency of sound determine sound beam.

A

true

24
Q

Axial resolution is also called

a. range
b. lateral
c. angular
d. transverse

A

range

25
Q

True or False
Axial resolution measures the ability of a system to display two structures that are very close together when the structures are parallel to the sound beam’s main axis.

A

True

26
Q

In soft tissue, a 4 cycle, 2MHz pulse has a pulse length equal to 5mm. What is the axial resolution?

A

1.54mm

27
Q

If there are more cycles in a pulse, the numerical value of radial resolution is more, less or the same?

A

More

28
Q

Lateral resolution is also called?

a. axial
b. range
c. depth
d. transverse

A

transverse

29
Q

Lateral resolution is imaged best in the near field with a SMALL, or LARGE diameter crystal?

A

Small

30
Q

EXTERNAL or INTERNAL focusing is the most common form of fixed focusing.

A

Internal

31
Q

True or false

Phased array means fixed focusing

A

False

32
Q

HIGH or LOW frequency transducers have the best resolution.

A

High

33
Q

Lateral resolution equals

A

beam diameter

34
Q

In clinical imaging, axial resolution ranges from?

A

.1 to 1.0mm

35
Q

When the number of cycles in a pulse increases while the frequency remains the same, the image quality IMPROVES, DEGRADES, REMAINS THE SAME.

A

Degrades

36
Q

True or False

Axial and lateral resolution are measured in distance.

A

True

37
Q

Since the high-frequency sound beams provide enhanced longitudinal and lateral resolution, why isn’t ultrasound with a frequency of 100MHz used in diagnostic imaging?

This was a bonus question…

A

Attenuation

38
Q

When displayed on an oscilloscope, the amplitude information of a B-mode is routed into the?

A

z-axis

39
Q

An A-mode display looks like?

A

skyline

40
Q

The M-mode appears as a group of?

A

horizontal wavy lines

41
Q

What is the only mode that provides information about a reflector’s changing location with respect to time?

A

M-mode

42
Q

With A-mode, what is displayed on the y-axis?

A

amplitude of the reflected signal

43
Q

Which of the display modes is mainly used for ophthalmology?

A

A-mode

44
Q

With B-mode, which axis is related to the strength of refection?

A

z-axis

45
Q

Which display mode is used primarily to assess the motion of cardiac walls?

A

M-mode

46
Q

With A-mode, what is displayed on the x-axis?

A

depth

47
Q

Which display mode was the first form of gray scale imaging?

A

B-mode

48
Q

Which display mode has an invisible dot that moves across the system’s display and with that brightness of the dot will indicate the strength of the reflection?

A

B-mode

Ultrasound Physics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions