Chapters 9-11 Final

Question 1

What is another name for the near field?

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

Answer 1

Fresnel Zone

Question 2

True or False

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

Answer 2

False

Question 3

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

Answer 3

Fresnel

Question 4

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?

Answer 4

1. 16mm
2. 8mm
3. 10cm
4. 11.64cm

Question 5

Which of the following terms does not belong?

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

Answer 5

Fraunhofer

Question 6

True or False

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

Answer 6

True

Question 7

Transducer diameter and focal depth are directly or inversely related?

Answer 7

directly

Question 8

Frequency and focal depth are directly or inversely related?

Answer 8

directly

Question 9

The smaller diameter PZT beam will create?

Answer 9

lower frequency and shallow focus

Question 10

The larger diameter PZT beam will create?

Answer 10

higher frequency and deep focus

Question 11

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?

Answer 11

6mm

Question 12

Crystal diameter and beam divergence are directly or inversely related?

Answer 12

inversely

Question 13

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

Answer 13

large

Question 14

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

Answer 14

Huygens

Question 15

True or False

Small transducer diameters produce a beam with less divergence.

Answer 15

false

Question 16

True or False

High frequency beams will produce less divergence.

Answer 16

True

Question 17

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

Answer 17

4mm diameter, 2MHz

Question 18

Lateral resolution is best at the?

Answer 18

focus

Question 19

Does Axial resolution change?

Yes or No

Answer 19

No

Question 20

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

Answer 20

higher frequency sound beams

Question 21

True or false

The sonographer can adjust the internal focusing.

Answer 21

False

Question 22

When a beam becomes focused, it?

Answer 22

has a focal zone that gets smaller

Question 23

True or False

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

Answer 23

true

Question 24

Axial resolution is also called

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

Answer 24

range

Question 25

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.

Answer 25

True

Question 26

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

Answer 26

1.54mm

Question 27

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

Answer 27

More

Question 28

Lateral resolution is also called? a. axial b. range c. depth d. transverse

Answer 28

transverse

Question 29

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

Answer 29

Small

Question 30

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

Answer 30

Internal

Question 31

True or false | Phased array means fixed focusing

Answer 31

False

Question 32

HIGH or LOW frequency transducers have the best resolution.

Answer 32

High

Question 33

Lateral resolution equals

Answer 33

beam diameter

Question 34

In clinical imaging, axial resolution ranges from?

Answer 34

.1 to 1.0mm

Question 35

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

Answer 35

Degrades

Question 36

True or False | Axial and lateral resolution are measured in distance.

Answer 36

True

Question 37

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...

Answer 37

Attenuation

Question 38

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

Answer 38

z-axis

Question 39

An A-mode display looks like?

Answer 39

skyline

Question 40

The M-mode appears as a group of?

Answer 40

horizontal wavy lines

Question 41

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

Answer 41

M-mode

Question 42

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

Answer 42

amplitude of the reflected signal

Question 43

Which of the display modes is mainly used for ophthalmology?

Answer 43

A-mode

Question 44

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

Answer 44

z-axis

Question 45

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

Answer 45

M-mode

Question 46

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

Answer 46

depth

Question 47

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

Answer 47

B-mode

Question 48

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?

Answer 48

B-mode