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Flashcards in Harmonics TEST Deck (22):
0

Harmonic imaging and contrast agents increase....

diagnostic accuracy

1

harmonics gets rid of what color?

some of the gray

2

How is the image created with harmonics?

by processing reflections that are twice the fundamental frequency
(aka incident, fundamental, central, transmitted main, resonant frequency)

arises from ***non linear behavior*** a multiple of two of the original frequency

3

what are the two kinds of harmonic imaging?

tissue harmonics

contrast harmonics

4

When is harmonics created?

durning transmission

5

What is THI or CHI

Tissue Harmonic Imaging

Contrast Harmonic imaging

6

What has made harmonics possible?

broadband technology has made this possible

increases signal to noise ratio

least likely to create artifacts

7

How does harmonics affect spatial resolution?

it increases detail or spatial resolution

decreases reverberation artifact

8

When you put the harmonics on is deep scanning the best?

no because the frequency is now higher and penetration is limited

9

If you have fundamental imaging what is the frequency?

finish slide 9

10

The fundamental frequency is filtered and the second harmonic echoes are passed. How does this affect lateral resolution and grating lobe artifacts?

narrower beam improves lateral resolution

eliminates grating lobe artifacts

11

What does harmonics do to the signal to noise ratio?

increases the signal to noise ratio

12

What three things increases the signal to noise ratio?

harmonics

power

persistence (frame average)

13

What does tissue harmonics enhance?

slide 14

14

Tissue harmonics helps with shadowing and ....

enhancement

15

what are the contrast agent requirements?

safe

metabolically inert

long lasting

strong reflector

small

easy administration

use microbubbles

16

With contrast harmonics what kind of index do you use?

mechanical index

set so you don't burst the contrast bubbles and cause tissue damage

17

Is contrast harmonics linear or non linear?

non linear

18

MI is related to the likelihood of bioeffects what are these scales?

slide 26

19

If you have a lower mechanical index what happens to harmonics?

in contrast harmonics

lower MI

slide 28

20

What is a conventional system?

no bells and whistles like harmonics and such

21

Compare tissue harmonics and contrast harmonics

Tissue Contrast

finish slide 31