Test 3

Question 1

T/F

Side lobes are created by array transducers.

Answer 1

False

Question 2

T/F

The PRF (pulse repetition frequency) is determined/controlled by the number of lines per frame and the frame rate?

Answer 2

True

Question 3

A sonographer who is using a phased array scanner changes from 4 focal zones to one. What is the most likely consequence of this action?

A)frame rate decreases
B)temporal resolution degrades
C) imaging depth increases
D) temporal resolution improves

Answer 3

D) temporal resolution improves

Question 4

Which of the following forms of resolution improves when frame rate increases?

A) lateral resolution
B) longitudinal resolution
C) temporal resolution
D) spatial resolution

Answer 4

C) temporal resolution

Question 5

The near zone length of a transducer depends on

A) propagation speed and frequency
B) frequency and transducer diameter
C) field of view and transducer diameter
D) path length and frequency

Answer 5

B) frequency and transducer diameter

Question 6

Grating lobes in electronic array systems

A) increase with increased steering angle
B) decrease with increased steering angle
C) are eliminated at high frame rates
D) are not likley to produce artifacts

Answer 6

A) increase with increased steering angle

Question 7

The frame rate of a real-time scanner that uses an electronic array depends on:

A) velocity of sound
B) the image depth
C) number of lines in the image
D) all of the above

Answer 7

D) all of the above

Question 8

Which of the following has a fixed focus and uses two crystals; one for transmitting and one for receiving?

A) A-Mode
B) M-mode
C) continuous wave mode
D) pulse-echo mode

Answer 8

C) continuous wave mode

Question 9

Of the choices below, which transducer would be well suited to intercostal scanning?

A) linear sequenced array, real-time
B) mechanical sector, real-time
C) static scanner with large diameter

Question 10

Which of the following transducers would be most useful for penetration of an obese patient?

A) 5 MHz, short focus
B) 3 MHz, long focus
C) 5 Mz, long focus
D) 2.5 MHz , short focus

Answer 10

B) 3 MHz, long focus

Question 11

Beam thickness artifacts primarily depend on

A) position of the patient
B) gas bubbles
C) beam angulation
D) gravity

Answer 11

C) beam angulation

Question 12

Which of the following varies with distance from the transducer?

A) SPL
B) axial resolution
C) frequency
D) lateral resolution
E) none of the above

Answer 12

D) lateral resolution

Question 13

A longer near zone can be obtained by _______.

A) using a higher frequency transducer
B) using a lower frequency transducer
C) decreasing the diameter of the transducer
D) increasing damping

Answer 13

A) using a higher frequency transducer

Question 14

T/F

Real time imaging is only possible with electronic arrays

Answer 14

False

Question 15

T/F

It is not possible to steer an annular phased array electronically

Answer 15

True

Question 16

T/F

The number of scan lines within a given area is called the line density

Answer 16

True

Question 17

T/F

Linear phased array scanners need no form of mechanical focusing in the elevational plane because focusing is performed electronically

Answer 17

False

Question 18

T/F

The beam diameter is constant in the near zone

Answer 18

False

Question 19

T/F

An annular array scanner uses mechanical beam steering

Answer 19

True

Question 20

T/F

A linear sequenced array can never be dynamically focused

Answer 20

False

Question 21

Lateral Resolution

A) and ring-down are the same
B) depends on the beam diameter
C) determines penetration depth
D) cannot be measured in the far zone

Answer 21

B) depends on the beam diameter