Ultrasound Imaging Parts

Question 1

What are the ultrasound imaging parts? (7)

Answer 1

1. transducer
2. pulser
3. beam former
4. receiver
5. memory
6. display
7. master synchronizer

Question 2

What does the beam former do?

Answer 2

It is the “brain” – it controls the phasing of the transducer. It figures out the timing of everything

Question 3

What does the pulser do?

Answer 3

It’s the “braun” – it creates the voltage needed to excite crystals & make the pulse. It tells memory & receiver that contact has been made with the probe

Question 4

Other names for the pulser voltage? (6)

Answer 4

Acoustic power, output power, transmit, output, energy output, output gain

Question 5

Does pulser voltage have bioeffects?

Answer 5

Yes – always use the lowest power possible

Question 6

What does the receiver do?

Answer 6

Preps information from signals that return to the probe then eventually displays them on the monitor

Question 7

What are the operations of the receiver?

Answer 7

Amplification
Compensation
Compression
Demodulation
Rejection

Question 8

What is another name for amplification?

Answer 8

Receiver gain

Question 9

What is amplification/receiver gain?

Answer 9

Small voltages are boosted and made stronger.

Question 10

What is the result of increasing amplification/receiver gain?

Answer 10

The image’s overall echogenicity is increased

Question 11

What is preamplification?

Answer 11

The process of improving the signal quality before it’s amplified. Large spikes are clipped and very weak signals are amplified

Question 12

Where is the preamplifier?

Answer 12

Between the transducer and amplifier

Question 13

What are the synonyms for compensation? (4)

Answer 13

1. Swept gain
2. Time gain compensation (TGC)
3. Depth gain compensation (DGC)
4. Line gain compensation (LGC)

Question 14

What does compensation do?

Answer 14

It compensates for attenuation because of depth for uniform echogenicity

Question 15

What are the synonyms for compression? (2)

Answer 15

1. Log compression
2. Dynamic range

Question 16

What is the relationship between dynamic range and compression?

Answer 16

Inversely related – compression/log compression are ACTIONS on the dynamic range

Question 17

What is dynamic range?

Answer 17

the range of amplitudes in the signal

Question 18

What is compression?

Answer 18

The ratio of the greatest to smallest amplitudes that can be handled by the US machine

Question 19

What happens when you increase dynamic range (DR)?

Answer 19

Increase dynamic range
Increase shades of grey
Decrease contrast
Increase contrast resolution
Smoother image

Question 20

What happens when you increase compression?

Answer 20

Increase compression
Decrease dynamic range
Decrease shades of grey
Decrease contrast resolution
More contrast!

Question 21

When would you want to drop dynamic range/increase compression?

Answer 21

When you need more contrast between two structures
Ex: cysts

Question 22

What is demodulation?

Answer 22

The process of changing voltages to another form more suitable for display

Question 23

What are the 2 parts of demodulation?

Answer 23

1. Rectification
2. Smoothing

Question 24

What is rectification?

Answer 24

Turning negative signals to positive signals

Question 25

What is smoothing?

Answer 25

Averaging the signals to remove "bumps" of voltage signal

Question 26

What are the synonyms for rejection? (4)

Answer 26

1. Suppression 2. Threshold 3. Filter 4. Wall filter

Question 27

What is rejection/suppression/filter/threshold?

Answer 27

The process of eliminating small voltage amplitudes

Question 28

What is the purpose of suppression?

Answer 28

To reduce noise in spectral and clutter in color doppler

Question 29

Which one of the receiver's operations is not user adjustable?

Answer 29

Demodulation

Question 30

What is the synonym for scan converter?

Answer 30

Memory

Question 31

What does the scan converter/memory do?

Answer 31

Stores information coming from the receiver

Question 32

What are the two ways to store data?

Answer 32

1. Analog 2. Digital

Question 33

What are the elements of digital scan converters? (2)

Answer 33

1. Pixels 2. Bits

Question 34

What is a pixel?

Answer 34

Picture element -- the smallest building block of digital pictures

Question 35

What is a bit?

Answer 35

Binary digit -- the smallest amount of computer memory

Question 36

What determines a pixel's shade of grey?

Answer 36

The number of bits it has

Question 37

What is contrast resolution?

Answer 37

The ability to show various shades of grey

Question 38

What is pre-processing?

Answer 38

Manipulating the image data before storage in the scan converter. This happens before freezing the image

Question 39

What are synonyms for write zoom?

Answer 39

RES (regional expansion selection), write zoom, HD

Question 40

What does RES/write zoom/HD do to the image?

Answer 40

It takes the ROI, rescans it, and this image has more scan lines and pixel density, leading to better spatial resolution

Question 41

Is RES/write zoom/HD pre or post processing?

Answer 41

Pre-processing

Question 42

Synonyms for persistence? (2)

Answer 42

Temporal compounding and temporal averaging

Question 43

What is persistence/temporal averaging/temporal compounding?

Answer 43

Purposely slowing the frame rate down with frame averaging to see a smoother image

Question 44

When is it a good time to use persistence?

Answer 44

When we're scanning bigger organs that don't move too much

Question 45

When should we turn persistence off?

Answer 45

When we're scanning anything that moves quickly -- echo

Question 46

What is fill-in interpolation?

Answer 46

When the machine fills in missing pixels by using pixel averaging due to scan line divergence

Question 47

What image formats use fill-in interpolation?

Answer 47

1. Sector 2. Blunted sector

Question 48

What is post-processing?

Answer 48

The manipulation of image data after storing in scan converter

Question 49

What are the synonyms for read zoom?

Answer 49

Read magnification, MAG, ZOOM

Question 50

Is read zoom/mag/zoom pre or post processing?

Answer 50

Post-processing

Question 51

What are the 2 synonyms for display?

Answer 51

1. TV monitor 2. Cathode ray tube (CRT)

Question 52

What are the 3 types of displays?

Answer 52

1. Interlaced display 2. Noninterlaced display/progressive scan 3. High res monitors/HD displays

Question 53

How do interlaced displays work?

Answer 53

Made up of 525 horizontal lines -- odd ones are written first & then even

Question 54

Disadvantage of interlaced displays?

Answer 54

Eye strain, especially for moving objects

Question 55

How to progressive scan/noninterlaced displays work?

Answer 55

Lines are written in sequence using raster scan

Question 56

What is the advantage of progressive scans?

Answer 56

Less eye strain

Question 57

How many horizontal lines do HD displays have?

Answer 57

1000+ lines

Question 58

What is the advantage of HD displays?

Answer 58

More lines + more pixels = better spatial resolution

Question 59

What are the two monitor controls that can also be found on printers?

Answer 59

Brightness & contrast

Question 60

What are the 5 ways to record & archive images?

Answer 60

1. multi-image camera 2. laser printer 3. thermal printer 4. color thermal printer 5. strip charts

Question 61

Which archiving system(s) use photographic emulsion film?

Answer 61

Multi-image camera & laser printer

Question 62

Which archiving system(s) use heat sensitive paper?

Answer 62

Thermal printers & color thermal printers

Question 63

Which archiving system uses strips of paper to record info?

Answer 63

Strip charts

Question 64

Advantages of multi-image camera for archiving?

Answer 64

Good spatial resolution

Question 65

Disadvantage of multi-image cameras for archiving? (2)

Answer 65

Photographic film needs storage space Retrieval problems

Question 66

Advantages of laser printers? (3)

Answer 66

Good spatial & grey-scale resolution More images on 1 sheet of film can save costs Film develops automatically which can save time and labor costs

Question 67

Disadvantages of laser printers? (2)

Answer 67

Storage & retrieval problems (like multi-image cameras) Printing systems are expensive

Question 68

Advantages of thermal printers? (2)

Answer 68

Portable & variable costs

Question 69

Disadvantages of thermal printers? (2)

Answer 69

Unstable archival storage Spatial & image resolution aren't as good as film

Question 70

Advantage of color thermal printers?

Answer 70

Full size color images

Question 71

Disadvantage of color thermal printers

Answer 71

Desktop printers -- not portable

Question 72

What are strip charts used for?

Answer 72

M-mode & spectral doppler information Fetal non-stress tests

Question 73

Advantages of strip charts? (2)

Answer 73

Portable Low-cost supplies

Question 74

What are the two types of magnetic recording devices?

Answer 74

1. Videotape casettes 2. Fiber optics

Question 75

Advantages of videotape cassettes? (2)

Answer 75

1. images can be recorded in real time 2. can be erased & written over

Question 76

Disadvantages of videotape cassettes? (2)

Answer 76

1. Magnetic tape becomes unstable overtime 2. Europe & Asia have different formats

Question 77

What are the two types of digital format storage options?

Answer 77

1. Magneto-optical disc 2. PACS/DIN/IMACS

Question 78

How do magneto-optical discs save images digitally?

Answer 78

They combine read/write capabilities of magnetic technology with storage capabilities of optical media

Question 79

What are the advantages of magneto-optical discs?

Answer 79

Think of them as hard drives/CD roms - more stable than VHS Info can be saved, deleted, rewritten

Question 80

What do PACS/DIN/IMACS stand for?

Answer 80

Picture archiving & communications system Digital imaging network Image management acquisition control system

Question 81

What does the local area network (LAN) do for PACS?

Answer 81

Links together acquisition, display, archiving, and hard copy components

Question 82

Advantages of PACS/DIN/IMACS? (4)

Answer 82

1. Teleradiology 2. Reduced necessity for different hard copy devices 3. Lower film costs 4. Lower time to retrieve images

Question 83

Disadvantages of PACS/DIN/IMACS? (4)

Answer 83

1. Complex 2. Expensive 3. Can be limited in spatial resolution 4. Reduced accuracy --> less time on scan since it's sent right away

Question 84

What are on the axes of A-mode?

Answer 84

X-axis: depth Y-axis: amplitude

Question 85

What are on the axes of M-mode?

Answer 85

X-axis: time Y-axis: depth & if there is motion or not

Question 86

What are on the axes of B-mode?

Answer 86

X-axis: depth Y-axis: none Z-axis: amplitude/brightness

Question 87

What are the 4 display modes in imaging?

Answer 87

1. A-mode 2. B-mode 3. M-mode 4. 3D

Question 88

What is temporal resolution?

Answer 88

Resolution relating to time

Question 89

What factors affect temporal resolution? (4)

Answer 89

1. Line density 2. Sector angle 3. Multiple focal zones 4. Imaging depth

Question 90

What is the relationship between penetration depth, focal zones, and lines per frame?

Answer 90

Depth x # Focal zones x Lines per frame