Study guide test 1

Question 1

The crystal is destroyed, and there is no image. What type of transducer is this?

Answer 1

mechanical

Question 2

What is the typical value for electrical single in phased array transducer?

Answer 2

10 nanoseconds

Question 3

What transducer creates a beam that is focused in all planes and all depths?

Answer 3

annular phased array

Question 4

What is the advantage of a 1 1/2 dimensional array transducer?

Answer 4

thinner beams with improved sliced thickness

Question 5

What type of resolution is improved by using a 1 1/2 dimension transducer?

Answer 5

elevational resolution

Question 6

What is the image shape for a vector array?

Answer 6

flat top sector (trapezoid)

Question 7

What transducer type has active elements arranged in rings?

Answer 7

Annular

Question 8

What type of transducer has active elements alligned in a straight line?

Answer 8

Linear

Question 9

What transducer has active elements that are bowed?

Answer 9

convex

Question 10

Phased array always means what?

Answer 10

adjustable multifocus

Question 11

Linear switch (sequential) has what type of steering?

Answer 11

electronic- phasing

Question 12

Drop out from top to bottom, what type of transducer will have that from a malfunction?

Answer 12

linear sequential (switched), convex sequential, 3D/4D

Question 13

What type of transducer has horizontal, side to side, drop out from a malfunction?

Answer 13

annular phased

Question 14

Which transducer is mechanically steered and fixed and singular focus?

Answer 14

mechanical

Question 15

The use of more active elements to receive reflections with a greater time of flight is called what?

Question 16

Displaying both real time and Doppler at the same time is known as?

Answer 16

Duplex imaging

Question 17

The ability to accurately locate moving structures at any particular instance is referred to as what type of resolution?

Answer 17

temporal resolution

Question 18

What determines temporal resolution and how is it affected?

Answer 18

It is determined by frame rate

high frame rate (high # of images) improves temporal resolution

Question 19

Which factors limit frame rate?

Answer 19

speed of sound in the medium

imaging depth

Question 20

What will affect the pulses in a single image?

Answer 20

number of focal points

sector size

line density

Question 21

If the imaging depth of view is doubled, what happens to the frame rate?

Answer 21

Frame rate decreases and degrades temporal resolution

Question 22

What will degrade temporal resolution?

Answer 22

deeper imaging

multiple focal points (improves lateral resolution)

wide sector

high line density (improves spatial resolution)

Question 23

What sector size uses fewer pulses?

Answer 23

narrow sector

Question 24

What’s the consequence of an action from changing the density of one line to three?

Answer 24

tightly packed lines

more pulses per frame

longer Tframe

lower frame rate

low temporal resolution

excellent spatial resolution

Question 25

What is a frame rate, and how long does it take to create a frame?

Answer 25

Tframe= # of pulses x PRP

system’s ability to create numerou frames each second

Question 26

When does lateral resolution improve?

Answer 26

with multi-focusing

Question 27

What is low line density and what type of image does it create?

Answer 27

line density-space between the sound beams

low line density- lines are spaced far apart, fewer pulses per frame, shorter Tframe, higher frame rate, high temporal resolution, poor spatial resolution

Question 28

What if we have a poor movie quality but a higher image quality?

Answer 28

multiple focusing

wide field of view

high line density (very tightly packed scan lines and small gaps)

Question 29

With line density, which improves what type of resolution and which decreases the other?

Answer 29

low line density- high temporal resolution, poor spatial resolution

high line density- low temporal resolution, excellent spatial resolution

Question 30

If the imaging depth of the scan is 15cm and there are 100 lines of image, what is the number of pulses making up the scan?

Answer 30

100

Question 31

Sonographer using a phased array system turns off the multi-focus system. What is the most likely consequence to happen?

Answer 31

temporal resolution improves

Question 32

What is spatial resolution and which line density improves it?

Answer 32

spatial resolution is the details in an image

High line density= excellent spatial resolution