Display and Image Processing Part 2

Question 1

Coded excitation improves what?

Answer 1

Image quality

Question 2

What kind of method is coded exitation?

Answer 2

a sophisticated method

Question 3

Where does coded excitation occur?

Answer 3

The pulser

Question 4

Does coded excitation use short or long pulses?

Answer 4

Uses long pulses. The computer uses long reflected pulses into high image quality.

Question 5

Why does coded excitation use long pulses?

Answer 5

To spread the energy of the beam over a broad range of frequencies.

Question 6

What are some advantages of coded excitation?

Answer 6

1. higher signal to noise ratio
2. improved axial resolution
3. improved spatial resolution
4. improved contrast resolution
5. deeper penetration

Question 7

What is coded excitation?

Answer 7

Long pulses with codes embedded with multiple shorter pulses.

Question 8

What is spatial compounding?

Answer 8

information from several different imaging angles to produce a single image. The frames are combined (overlapped or compounded) to form a single real-time image.

Question 9

Does spatial compounding need more or less frames to improve image quality?

Answer 9

More frames the better.

Question 10

What are some disadvantages of spatial compounding?

Answer 10

1. reduced frame rate
2. phased array transducer only

Question 11

What kind of transducer is used with spatial compounding?

Answer 11

Phased array transducer only

Question 12

Spatial compounding reduces what?

Answer 12

1. shadowing artifact
2. speckle (noise) artifact

Question 13

What is Edge Enhancement?

Answer 13

the computer identifies and emphasizes sharp-edge boundaries in the image with different gray scale levels.

Question 14

How is edge enhancement achieved by?

Answer 14

1. Increase image contrast immediately around the edges.

Question 15

What is frequency compouning?

Answer 15

processes different frequencies all at once instead of sequentially.

Question 16

Frequency compounding creates improved….

Answer 16

spatial and contrast resolution.

Question 17

What does temporal compounding do?

Answer 17

is a processing technique that continues to display info from older images. Previous frames are superimposed on the most current frame.

Question 18

What are some other names for Temporal compounding?

Answer 18

1. persistence
2. Temporal averaging

Question 19

Persistence is most effective when?

Answer 19

with slowly moving structures

Question 20

What is a primary limitation with temporal compounding?

Answer 20

reduction in the displayed frame rate, which reduces temporal resolution.

Question 21

How is edge compounding helpful?

Answer 21

Improves visualization of borders by
increasing image contrast around the edge

Question 22

How is edge compounding helpful?

Answer 22

Useful to emphasize different tissue.

Question 23

What is fill-in-interpolation?

Answer 23

Ultrasound system predicts the “missing” information based on gray scale of neighboring pixels

Question 24

is fill in interpolation pre or post processing?

Answer 24

pre-processing

Question 25

What is elastography?

Answer 25

stiffness data and ultrasound reflections are combined into images.

Question 26

With frequency compounding, how many pulses are transmitted down each scan line?

Answer 26

1

Question 27

What technique is used to create image data where non really exists?

Answer 27

Fill-in-interpolation