Final Exam

Question 1

A finer speckled pattern generally has a higher transmit frequency. True or false?

Answer 1

True

Question 2

Attenuation is expressed as Db(cm – MHz) the dash and the denominator indicates?

Answer 2

The depth and frequency affect attenuation

Question 3

Which of the following listed is not a scanned modality?

• Sequentiale generated 2-D imaging
• PW Doppler
• Sequential generated color flow imaging
• 3-D imaging

Answer 3

• PW Doppler

Question 4

What change would occur to the duty factor if the PRP increased by a factor of three?

Answer 4

Duty factor would decrease by a factor of three

Question 5

What generally limits the maximum power allowed in non-scan modalities?

Answer 5

Risk of thermal bio effects

Question 6

List four non-scan modalities of ultrasound.

Answer 6

• CW
• PW
• A mode
• M Mode

Question 7

Define sampling rate.

Answer 7

The frequency of which signals are detected or assessed

Question 8

Define frame time.

Answer 8

The time required to produce an image

Question 9

Define acoustic beam.

Answer 9

A single transmit event in a specific direction and the associated echoes

Question 10

Define frame rate.

Answer 10

The reciprocal of frame time

Question 11

Define display line.

Answer 11

The data displayed on the screen that corresponds to a single direction within the patient

Question 12

Define pulse wave.

Answer 12

A transmit beam that is turned on and off to provide range ambiguity

Question 13

Define image.

Answer 13

To receive data for a specific time period formatted as a picture

Question 14

Define receive beam.

Answer 14

The returning echo

Question 15

What is the highest achievable axial resolution if the spatial pulse length is 12 mm?

Answer 15

Axial resolution equals SPL divided by two. So 12 ÷ 2 = 6.

Question 16

What are the two ways to achieve better axial resolution as related to SPL equation?

Answer 16

• Shorter wavelength
• Fewer cycles in the pulse

Question 17

The minimum PRP is the reciprocal of the maximum PRF. True or false?

Answer 17

True

Question 18

Calculate the frame time for the sequential imaging scenario depicted.

Answer 18

Frame time equals 13 µs divided by centimeters times imaging depth divided by number of lines times number of lines

Question 19

What would increase the frame rate?

• Decrease depth
• Decrease width
• Zoom
• All the above

Answer 19

• All the above

Question 20

What imaging technique is depicted by the following figure?

Answer 20

• Plane wave imaging
• Sequential
• Parallel processing ✅

Question 21

Plain wave imaging is a scanned or non-scan modality?

Answer 21

Non-scanned

Question 23

What frequency does a Pedof probe normally operate when used in cardiac imaging?

Answer 23

1.9 MHZ

Question 24

What was the main limitation of a mechanical transducer?

Answer 24

no ability to vary the focus

Question 25

Annular rays allow for variable focus, both lateral and elevation planes. True or false?

Answer 25

true

Question 26

Name the process

Answer 26

sequencing

Question 27

Name the process using kerfs.

Answer 27

dicing

Question 28

Dicing allows the creation of an array to be able to cut into a series of independent but still connected elements. True or false?

Answer 28

true

Question 29

Which element receives a signal earlier?

Answer 29

eight

Question 30

This profile shows what?

Answer 30

both focus and steering

Question 31

This transducer is used for what purpose?

Answer 31

Cardiac imaging

Question 32

A cardiac ultrasound probe creates a sector scan by phasing. True or false?

Answer 32

true

Question 33

Trapezoid scanning was created to produce a smaller field of view. True or false?

Answer 33

False

Question 34

What happens when the number of image lines is increased?

Answer 34

Expands field of view, increases frame time, but decreases temporal resolution

Question 35

What is the effect of narrower beams on lateral resolution?

Answer 35

Potentially improves lateral resolution but requires higher line density

Question 36

What does a larger transmit aperture increase?

Answer 36

Focal depth, penetration depth, creates a narrower beam in the immediate far field

Question 37

What is a disadvantage of a larger transmit aperture?

Answer 37

Decreases lateral resolution and can potentially increase the risk of bio effects

Question 38

What does line/frame averaging improve?

Answer 38

Signal noise ratio and sensitivity

Question 39

What is an advantage of averaging?

Answer 39

More speckle reduction

Question 40

If averaging improves the signal to noise ratio by a factor of three, how many samples are most likely used in the average?

Answer 40

Nine or 10

Question 41

Averaging techniques are based on the concept of what?

Answer 41

Constructive and partial constructive interference

Question 42

Which mode is an example of a line averaging technique?

Answer 42

Colored Doppler

Question 43

The associated figures used to describe..

Answer 43

FIFO buffering

Question 44

Which of the following is not an advantage of compound imaging?

Answer 44

Improved temporal resolution

Question 45

What technique entails transmitting with a broadband signal and simultaneously processing more than one image at a different frequency?

Answer 45

Frequency compounding/fusion

Question 46

Which statement about multiple transmit foci is not true?

Answer 46

If there are 4 foci, the frame rate decreases by a factor of 4

Question 47

What receive technique is depicted by the associated image?

Answer 47

Continuous dynamic receiver focusing

Question 48

The term synthetic aperture refers to what?

Answer 48

The effective aperture created by adding signals from individual elements

Question 49

True or False: The term synthetic aperture refers to the effective aperture created by adding signals from individual elements.

Answer 49

True

Question 50

Match the following transmit beam plot with the correct term: single focus, larger aperture, dynamic, retrospective, beam, parallel processing, single focus small aperture.

Answer 50

Look it up

Question 51

What is a disadvantage of multifocal sequence?

Answer 51

Degrades temporal resolution

Question 52

True or False: Retrospective transmit focus improves lateral resolution and has disadvantages related to processing power.

Answer 52

True

Question 53

True or False: Multi line transmit decreases the frame rate.

Answer 53

False

Question 54

Match the following images with the correct term

Answer 54

D A C B