Socrative Review

Question 1

Which Method of isolating harmonics frequencies resulted in degraded detail resolution?

Answer 1

Filtering our the operating frequencies, that way we can get the desired harmonic frequencies back.

Question 2

Why is there a potential safety consideration in using harmonic imaging

Answer 2

Higher intensities

Question 3

User modern day harmonics, what aspects of resolution are improved? Are any compromised?

Answer 3

Temporal resolution because now we have to fire two pulses.

Question 4

Explain all of the things associated with a narrowband width?

Answer 4

1. Narrow band width = long pulse length = worse axial resolution
2. High Q.
3. Increased cycles per pulse
4. Increased pulse duration
5. Increased duty factor

Question 5

Explain how a machine can use coded excitation to visualized blood flow with 2D scanning known as B-flow?

Answer 5

Digital encoder that codes non real pulses to code and encoders real pulses into B mode imaging

Question 6

What are advantages and disadvantages of B flow?

Answer 6

1. Disadvantage: Unable to differentiate between direction when we have still image
2. Advantage: No need to send so many pulses unlike colour
3. Advantage: Full field of view vs a small sample size
4. Disadvantage: Unable to determine velocity, without using spectral

Question 7

What is the dominant factor relating to speed of sound in a medium?

Answer 7

Stiffness, When sound propagates through tissue where there are issues of increased tissue?

Question 8

What is the difference of axial and lateral resolution?

Answer 8

Lateral resolution that is perpendicular to the path of the beam.
Axial resolution changes with depth 1/2 SPL
Lateral resolution is increased by focusing
LARD ( Longitude, resolution, distance)
LATA (Lateral, azimuthal, transverse, Angular)