Physics 2 Test chapters 14 &15

Question 1

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

Answer 1

Master synchronizer

Pg 216

Question 2

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

Answer 2

Pulser

Pg 217

Question 3

Know the anatomy of a TGC curve

Answer 3

Near gain
Delay
Slope
Knee
Far gain
Pg 228

Question 4

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

Answer 4

Beam Former

Pg 221

Question 5

What are all of the receiver functions?

Answer 5

Amplification 
Compensation
Compression
Demodulation
Reject
Pg 223

Question 6

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

Answer 6

Voltage

Pg 237

Question 7

What type of pulser generates constant electrical signal?

Answer 7

Continuous wave

Pg 236

Question 8

What is the receiver function that will improve signal to noise?

Answer 8

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

Question 9

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

Answer 9

Rectification
Or
Smoothing

Pg 232

Question 10

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

Answer 10

Compression

Gray scale

Pg 230

Question 11

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

Answer 11

Demodulation

Pg 232

Question 12

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

Answer 12

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

Question 13

Which receiver function treats signals differently depending on depth?

Answer 13

Compensation

Pg 226

Question 14

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

Answer 14

Reject

Pg 233

Question 15

When PRP is long, PRF will be?

Answer 15

Lower

Pg 220

Question 16

Know all six components of an ultrasound system

Answer 16

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

Question 17

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

Answer 17

Adjust the systems compensation

pg 238

Question 18

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

Answer 18

Decrease the output power

pg 238

Question 19

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

Answer 19

Amplification

Pg 224

Question 20

What are some disadvantages of analog scan converters?

Answer 20

image fade
image flicker
instability
deterioration
pg 243

Question 21

Which electronic component is required for gray scale imaging?

Answer 21

scan converter??
pg. 241
Analog Scan Converter? (Pg. 243

Question 22

Read magnification

Answer 22

A part of a frozen image is zoomed up on and it makes the image distorted. Number of pixels stay the same they are just larger.
pg 250

Question 23

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

Answer 23

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

Question 24

Advantages of an analog scan converter

Answer 24

The spatial resolution (image detail) is excellent because of the large number of storage elements.
These numbers can be unlimited and continuous range of values.
pg 242 maybe more???
Real World Numbers

Question 25

How to calculate how many shades of gray there are (pg. 246)

Answer 25

for example: how many possible shades of grey if you have 3 bits. (2x2x2=8) pg 246

Question 26

How many bits are needed to store certain amount of shades of gray (how to calculate this)

Answer 26

I bet the question is going to be like #9 on the Q&A pg 262

Question 27

What are the preprocessing functions?

Answer 27

``` 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 ```

Question 28

Know about pixels

Answer 28

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

Question 29

Know the diagram on pg. 247 about digital and analog

Answer 29

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

Question 30

Bistable imaging

Answer 30

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

Question 31

Spatial resolution of the CRT is determined by what? (Beth said "CRT" means "screen/monitor")

Answer 31

Pixel density | Pg. 377

Question 32

What function is related to the ability for us to see shades of gray?

Answer 32

Compression | pg 230

Question 33

Real world vs. computer world

Answer 33

real world is analog and computer world is digital | 242

Question 34

While scanning, you increase your overall gain. Is this preprocessing or postprocessing?

Answer 34

Preprocessing | pg. 249

Question 35

Preprocessing

Answer 35

The manipulation of image data before storage in the scan converter; sonographer controls this; alters image data forever and cannot be reversed/undone pg. 249

Question 36

Postprocessing

Answer 36

The manipulation of image data after storage in the scan converter; sonographer controls this; since this occurs after A-to-D conversion and storage, all changes can be reversed; any alterations to a frozen image must be postprocessing ``` Any change after freeze frame Black/white inversion Read magnification Contrast variation 3-D rendering pg. 249 ```

Question 37

What portion converts data into numbers?

Answer 37

Digital scan converter | Pg. 243

Question 38

What are the advantages of coded excitation?

Answer 38

``` Higher signal-to-noise ratio Improved axial resolution Improved spatial resolution Improved contrast resolution Deeper penetration pg. 253 ```

Question 39

What is fill-in interpolation?

Answer 39

Fill in the gaps of missing data in a way that cannot be detected by the observer; form of preprocessing pg. 257

Question 40

What is coded excitation? (where does it occur)

Answer 40

Creates very long sound pulses containing a wide range of frquencies. Occurs in the pulser. pg. 253

Question 41

What is spatial compounding?

Answer 41

Using sonographic information from several different imaging angles to produce a single image pg. 254

Question 42

What is elastography?

Answer 42

Produces images from sound reflection. Theory of elastography is that tissue will deform differently following the application of a force. Estimates tissue stiffness. pg 258

Question 43

Which technology reduces speckle and improves spatial resolution?

Answer 43

Spatial compounding | pg. 254

Question 44

What is speckle?

Answer 44

is noise resulting from constructive and destructive interference of small sound wavelets. pg 374

Question 45

Which technology provides a history of past frames that overlay on the present frames?

Answer 45

temporal compounding, persistence, or temporal averaging | pg 256