Study guide test 1 Flashcards Preview

Spring: Physics > Study guide test 1 > Flashcards

Flashcards in Study guide test 1 Deck (32):
1

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

mechanical

2

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

10 nanoseconds 

3

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

annular phased array

4

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

thinner beams with improved sliced thickness

5

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

elevational resolution

6

What is the image shape for a vector array?

flat top sector (trapezoid)

7

What transducer type has active elements arranged in rings?

Annular

8

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

Linear

9

What transducer has active elements that are bowed?

convex

10

Phased array always means what?

adjustable multifocus

11

Linear switch (sequential) has what type of steering?

electronic- phasing

12

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

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

13

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

annular phased

14

Which transducer is mechanically steered and fixed and singular focus?

mechanical

15

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

16

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

Duplex imaging

17

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

temporal resolution

18

What determines temporal resolution and how is it affected?

It is determined by frame rate

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

19

Which factors limit frame rate?

speed of sound in the medium

imaging depth

20

What will affect the pulses in a single image?

number of focal points

sector size

line density

21

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

Frame rate decreases and degrades temporal resolution

22

What will degrade temporal resolution?

deeper imaging

multiple focal points (improves lateral resolution)

wide sector

high line density (improves spatial resolution)

23

What sector size uses fewer pulses?

narrow sector

24

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

tightly packed lines

more pulses per frame

longer Tframe

lower frame rate

low temporal resolution

excellent spatial resolution

25

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

Tframe= # of pulses x PRP

system's ability to create numerou frames each second

26

When does lateral resolution improve?

with multi-focusing

27

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

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

28

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

multiple focusing

wide field of view

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

29

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

low line density- high temporal resolution, poor spatial resolution

high line density- low temporal resolution, excellent spatial resolution

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?

100

31

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

temporal resolution improves

32

What is spatial resolution and which line density improves it?

spatial resolution is the details in an image

High line density= excellent spatial resolution