Chapter 17

Question 1

The 5 Requirements of Contrast Agents

Answer 1

-Safe
-Metabolically Inert
-Long Lasting
-Strong reflector of ultrasound
-Small enough to pass through capillaries

Question 2

If the fundamental frequency 5 what is the harmonic frequency?

Answer 2

10

Question 3

What’s the synonym for harmonic imaging?

Answer 3

Second harmonic frequency

Question 4

Harmonic frequency sound arises from ____ behavior

Answer 4

Non linear

Question 5

What does pulse inversion reduce?

Answer 5

Temporal resolution

Question 6

What’s the major disadvantage of pulse inversion?

Answer 6

Degrades temporal resolution

Question 7

What improves spatial resolution

Answer 7

Pulse inversion

Question 8

Frame rate is 1/2 of the ____ _____

Answer 8

Fundamental frequency

Question 9

Harmonics are typically ___ of the fundamental

Answer 9

Twice

Question 10

What are the two methods are being isolated from the fundamental beam

Answer 10

-pulse Inversion harmonics
-power modulation harmonics

Question 11

When dealing with contrast harmonics, does high pressure point shrink or expand the bubble?

Answer 11

Shrink

Question 12

Which is stronger contrast harmonics or tissue

Answer 12

Contrast

Question 13

Does sound move faster in compression or rarefraction?

Answer 13

Compression

Question 14

Resonance is

Answer 14

The nonlinear (uneven) changes in bubble size

Question 15

Best harmonic effect is in the ____ field

Answer 15

Mid

Question 16

When is harmonics the strongest?

Answer 16

In the far field

Question 17

Will weak or strong beams create harmonics?

Answer 17

Strong

Question 18

What will only make harmonics?

Answer 18

The strong, central part of the beam

Question 19

What are the two ways harmonics are processed

Answer 19

1. Pulse inversion harmonics (most common)
2. Power modulation harmonics

Question 20

T/F Two pulses are sent down each scan line, the second pulse is 3x the size of first one sent.

Answer 20

False. It’s 2x

Question 21

What happens if MI is high?

Answer 21

The bubbles expands too much and pop.

Question 22

If MI is too low

Answer 22

The bubbles contract and expand evenly(no harmonics)

Question 23

What are the two contrast agent characteristics

Answer 23

1. The nature of the outer shell
2. The gas that fills the microbubbles

Question 24

When are contrast agents created?

Answer 24

During reflection