Chapter 12 quiz

Question 1

The minimum number of active elements in a mechanical transducer is:

Answer 1

1

Question 2

T or F. Many active elements fire at almost the same time in a phased array scanner.

Answer 2

True

Question 3

Which of the following transducers is best describes as mechanically steered and fixed, single focused?

Answer 3

Mechanical

Question 4

Which of the following is best described as mechanically steered and multi-focus?

Answer 4

Annular phased array transducer

Question 5

Which of the following transducers creates a rectangular shaped image?

Answer 5

Linear sequential array

Question 6

A linear phased array transducer has 128 crystals. How many of these crystals are fired to create a single sound beam?

Answer 6

128 (All of them)

Question 7

A linear sequential array transducer has 128 crystals. How many of these crystals are fired to create a single sound beam?

Answer 7

A small group

Question 8

In a linear phased array, what is the firing pattern that steers a beam up or down?

Answer 8

Slope

Question 9

In a linear phased array, what is the firing pattern that focuses a sound beam?

Answer 9

Curve

Question 10

T or F. There are large time delays in the firing pattern that focuses a sound beam.

Answer 10

False

Question 11

T or F. A machine that displays A-mode and two-dimensional images is called a duplex scanner.

Answer 11

False

Question 12

When looking at image produce by these transducer systems, which one can be distinguished from all the others?
Linear phased array
Linear switched array
Annular phased array
Mechanical transducer

Answer 12

Linear switched array

Question 13

T or F. All phased array transducer systems direct ultrasound pulses in many directions to create a two-dimensional image.

Answer 13

True

Question 14

What is true of the electrical pulses that excite the active elements of an annular phased array transducer?

Answer 14

They arrive at each PZT crystal at different times microseconds apart

Question 15

The pattern of electrical signals exciting the PZT crystals of a linear phased array transducer ________.

Answer 15

Typically changes from one acoustic pulse to the next

Question 16

How are PZT crystals excited when using an ultrasound system with sequential linear array transducer?

Answer 16

In a specific order

Question 17

How are the PZT crystal of a linear phased array transducer fired?

Answer 17

At almost exactly the same time

Question 18

T or F. The “curvature pattern” of delays in the electrical spikes used in linear phase array transducer focuses the beam during transmission.

Answer 18

True

Question 19

Which of the following forms of focusing is different that the others?
Lens
Mirror
Phased
Dynamic recieve

Answer 19

Mirror

Question 20

T or F. The “curved pattern” of delays in the electrical spikes used in linear phase array transducer focuses the beam during reception.

Answer 20

False

Question 21

Which two of the following terms are associated with phased array transducer?

Answer 21

Adjustable

Multi-focus

Question 22

What helps to determine the frequency of the sound produced by the transducer of a continuous wave ultrasound system?

Answer 22

Ultrasound system electronics

Question 23

What is the shape of the elements in an annular phased array transducer?

Answer 23

Circles

Question 24

Which best describes the element in a linear phased array transducer?
Rectangular, 1/4 wavelength thick
Rectangular, 1/2 to 1/4 wavelength wide
Circular
Squares, 1/2 wavelength thick

Answer 24

Rectangular, 1/2 to 1/4 wavelength wide

Question 25

Which best describes the element in a linear sequential array transducer?
Rectangular, 1/4 wavelength thick
Rectangular, 1/2 to 1/4 wavelength wide
Circular
Squares, 1/2 wavelength thick

Answer 25

Circular

Question 26

What image is created with a two-dimensional array transducer?

Answer 26

3D real time image

Question 27

All of the following describe dynamic receive focusing except:
Delay pattern change continuously throughout reception
May be used by single crystal transducers
Focusing occurs at many depths
Automatically performed by system

Answer 27

May be used by single crystal transducer

Question 28

Which transducer possesses the best slice thickness resolution?

Answer 28

1 1/2 dimensional arrays

Question 29

While using a linear sequential array transducer during a color doppler exam, the shape of the grayscale image is most often _________, whereas the shape of the color doppler portion of the image is __________.

Answer 29

Rectangular

Parallelogram

Question 30

Numerical value is higher in _______ and lower in _______.

Answer 30

Axial resolution

Lateral resolution

Question 31

Lateral resolution has to do with _______.

Answer 31

Width