Physics Test Ch. 14 and 15 Flashcards Preview

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Flashcards in Physics Test Ch. 14 and 15 Deck (49)
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1

Which component of an Ultrasound system is responsible for organization and time?

Master synchronizer Pg 216

2

Which component of an Ultrasound system creates an electrical signal that excites the PZT?

Pulser Pg 217

3

The anatomy area of the TGC curve where attenuation occurs

Slope

4

What part creates the firing pattern for a phased array system?

Beam Former Pg 221

5

What are all of the receiver functions?

1.Amplification
2.Compensation
3.Compression
4.Demodulation
5.Reject Pg 223

6

Acoustic power of a sound beam is determined by what part of a pulser?

Voltage Pg 237

7

What type of pulser generates constant electrical signal in the form of a sine wave?

Continuous wave Pg 236

8

What is the function that will improve signal to noise?

increasing output power is the most common way to improve signal to noise pg 219

9

What is the receiver function that has to do with demodulization?

Rectification Or Smoothing Pg 232

10

What is the receiver function that keeps ______ within range of the human eye?

Compression Gray scale Pg 230

11

What is the receiver function that is not adjustable by the sonographer?

Demodulation Pg 232

12

When an image is too dark or too bright, what are your two options to adjust the image?

output power (if image is too bright) and receiver gain (if image is too dark)

13

Which receiver function treats signals differently depending on depth?

Compensation Pg 226

14

What is the receiver function that affects the weak signals, leaving the strong signals unchanged?

Reject Pg 233

Also known as suppression and threshold

15

When PRP is long, PRF will be? And how does this affect listening?

-Lower
-Longer listening time
Pg 220 (deep imaging)

16

Know all six components of an ultrasound system

-Transducer
-Pulser and beam former
-Receiver
-Display
-Storage
-Master synchronizer Pg 216

17

What should you do if an ultrasound system displays reflectors only in the far region?

Adjust the systems compensation pg 238

18

What is the best choice if the entire image is too bright?

Decrease the output power pg 238

19

Which component will affect strength of every pulse transmitted into the body?

Amplification Pg 224

20

What are some disadvantages of analog scan converters?

-image fade
-image flicker
-instability
-deterioration pg 243

21

Which electronic component is required for gray scale imaging?

Scan converter

22

Read magnification

Occurs after the image data is stored in the scan converter; displaying original data.
Number of pixels in the image stay the same which makes the pixels larger when zoomed in p250

23

Temporal resolution may be improved if the region of interest is _____ in comparison to the original?

If the bottom of the region of interest is shallower that the original image's depth of view pg. 252

24

Advantages of an analog scan converter

Unlimited and continuous range of values
Real world-numbers that are found in our everyday lives
Spatial resolution is improved because of the large number of storage elements

25

How many shades of gray are represented by 5 bits

32
2*2*2*2*2=32

26

How many bits are needed to store certain amount of shades of gray.
Example: 10 shades of gray? 11 shades of gray? 15 shades of gray?

Four bits are required to store from 9 to 16 shades of gray

27

What are the preprocessing functions?

All the changes made to an image before storage.
-time gain compensation
-log compression
-write magnification
-persistence
-spatial compounding
-edge enhancement
-fill in interpolation pg 249

28

Know about pixels

Smallest building block of a digital picture; number of picture elements per inch
-Low pixel density:
few pixels/inch
larger pixels
less detailed image
lower spatial resolution
-High pixel density:
many pixels/inch
smaller pixels
more detailed image
higher spatial resolution pg. 244

29

Know the diagram on pg. 247 about digital and analog

analog------->analog-to-digital converter -------> digital memory (zeros and ones) -------> digital-to-analog converter --------> analog pg. 247

30

Bistable imaging

Images are composed of black and white shades only. pg 239