Ch 16, 17 Quiz Review Flashcards Preview

DMSO Physics 2 > Ch 16, 17 Quiz Review > Flashcards

Flashcards in Ch 16, 17 Quiz Review Deck (12):
1

What the requirements are for contrast?

Safe
Metabolically inert
Long lasting
Strong reflector for ultrasound
Small enough to pass through capillaries

2

Fundamental frequency, what is the harmonic frequency and vise versa?

Harmonic frequency is double the fundamental

3

What behavior creates harmonics?

Non-linear

4

Difference between few and many shades of gray?

Few Shades

few choices
bistable
narrow dynamic range
high contrast

5

Difference between few and many shades of gray?

Many Shades

many choices
gray scale
wide dynamic range
low contrast

6

Difference between contrast and tissue harmonics?

Contrast Harmonics

created during reflection off of microbubbles
occurs only when contrast agents are present and with MIs greater than 0.1
results from nonlinear behavior of microbubbles
stronger harmonic signal

7

Difference between contrast and tissue harmonics?

Tissue Harmonics

created during transmission
occurs as sound propagates in tissue
results from nonlinear behavior of transmitted sound beam
weaker harmonic signal

8

MI, know how it is calculated?

Peak Rarefraction Pressure / √Frequency

9

Pulse Inversion

The positive and negative reflections are combined.
The fundamental portions are eliminated, leaving only the harmonic part of the reflection.
Designed to utilize harmonic reflection free, while eliminating distorted fundamental reflections.

10

Low MI: <0.1

No harmonics
backscatter
linear behavior
higher frequency
low beam strength
bubble expands very little

11

Higher MI: 0.1-1.0

Some harmonics
resonance
nonlinear behavior
lower frequency
higher beam strength
bubble expands moderately

12

Highest MI: > 1

Strongest harmonics
bubble disruption
extreme nonlinear behavior
lowest frequency
highest beam strength
bubble expands greatly