111- Digital Imaging

Question 1

Binary code uses what two symbols

Answer 1

0 & 1

Question 2

How many bits make up a bite

Answer 2

8

Question 3

What is a PSP made of

Answer 3

Barium fluorohalide with europium activators

Question 4

What is the initial response with CR

Answer 4

Linear

Question 5

When/how is the latent image made

Answer 5

After exposure, when electrons are trapped in a higher energy state in the phosphor

Question 6

When/how is the manifest image made

Answer 6

When red laser scans plate, electrons give off blue light

Question 7

When is a CR plate most sensitive to scatter

Answer 7

After exposure

Question 8

What is the exposure data recognition

Answer 8

Useful Information used to create histogram

Question 9

What are the useful values of a histogram

Answer 9

Minimum and maximum values

Question 10

If a histogram can not detect collimated edges, what happens to the image

Answer 10

Too light or dark

Question 11

CR reader process:

Answer 11

Cassette lowered into reader/laser beam scans cassette/blue light photons emitted/light photons picked up by photodiode/electrical signal is created/sent to ADC/digital data sent to computer

Question 12

White and linear artifacts on images means:

Answer 12

A scratch was obtained in reader

Question 13

Direct capture pathway

Answer 13

X-ray tube/beam/photoconductor (amorphous selenium)/ TFT/analog signal/ADC/digital signal

Question 14

Indirect capture pathway

Answer 14

X-ray tube/beam/scintillator/light/CCD or CMOS (or photodiode;amorphous silicon and TFT) /analog signal/ADC/digital signal

Question 15

What is the scintillator made of

Answer 15

Cesium iodide or gadolinium oxysulfide

Question 16

When is a TFT used

Answer 16

In direct and indirect capture

Question 17

What is the interphase message called between HIS and RIS

Answer 17

HL7

Question 18

If you increase bit depth, what happens to resolution

Answer 18

Increases

Question 19

Main controlling factor of resolution

Answer 19

Pixel size

Question 20

Imaging system with best resolution (highest to lowest)

Answer 20

Film, CR(direct capture), DR

Question 21

If you decrease pixel pitch, what happens to resolution

Answer 21

Increases

Question 22

Is it more desirable to use a high or low kvp with DR

Answer 22

High

Question 23

4 factors that control contrast

Answer 23

Kvp, WW, LUT, automatic rescaling

Question 24

Insufficient light produced by the IP causes:

Answer 24

Graininess

Question 25

An undesired effect with edge enhancement

Answer 25

Increase in noise

Question 26

Undesired effect of low pass filtering

Answer 26

Loss of fine detail

Question 27

What is masking

Answer 27

Suppressing pixel values

Question 28

What does equalization do

Answer 28

Evens brightness

Question 29

How to calculate size of pixels in a matrix

Answer 29

FOV / matrix

Question 30

If the exposure is too high or too low, what can bring it back into diagnostic quality

Answer 30

Automatic rescaling

Question 31

What does oversaturation look like on an image

Answer 31

Overall loss of contrast, very gray

Question 32

What does MTF relate to

Answer 32

Speed class, fidelity, accuracy, absorption coefficient

Question 33

What is the purpose of a reference histogram

Answer 33

To bring any exposure into the ideal brightness, density, and contrast levels

Question 34

What causes a wraparound image

Answer 34

Aliasing, Moire effect

Question 35

What is an exposure latitude

Answer 35

Multiple exposures on different patients that are all fit within diagnostic quality

Question 36

What is quantization

Answer 36

Assigning of digital densities to each pixel

Question 37

What layer of the IP is the “active layer”

Answer 37

Phosphor layer

Question 38

What are the two types of phosphors

Answer 38

Turbid and needle

Question 39

Does direct or indirect capture give the best spatial resolution

Answer 39

Direct

Question 40

Does direct or indirect capture give the lowest patient dose

Answer 40

Indirect

Question 41

What is the purpose of the DEL

Answer 41

Collect electrons and represent the exposure level, essentially pixels

Question 42

What is DQE

Answer 42

Sensitivity and accuracy by which the IR converts incoming data to viewing device

Question 43

What is the perfect DQE

Answer 43

100%

Question 44

What happens to speed if you increase kvp

Answer 44

Increase

Question 45

What type of detectors have the highest DQE

Answer 45

Amorphous selenium

Question 46

What are the minimum values of the histogram

Answer 46

Whites

Question 47

What are the maximum values of the histogram

Answer 47

Blacks

Question 48

What are the two forms of histogram analysis

Answer 48

Priori and neural

Question 49

Priori uses how many histograms

Answer 49

1

Question 50

Neural uses how many histograms

Answer 50

Two or more

Question 51

What determines the size of the pixels

Answer 51

The matrix

Question 52

Spatial location domain is based on:

Answer 52

X and Y locations for each pixel

Question 53

Spatial frequency domain is based on:

Answer 53

Number of cycles per unit length

Question 54

What is the mathematical algorithm applied to change an image from spatial location domain to spatial frequency domain

Answer 54

Fourier transformation

Question 55

If you increase window width, what happens to contrast

Answer 55

Decreases

Question 56

If you increase window level, what happens to brightness

Answer 56

Gets darker

Question 57

What is automatic shuttering

Answer 57

Blackening our the white collimation borders

Question 58

High sampling frequency does what to detail and storage

Answer 58

Increase detail | Decrease storage

Question 59

2.5 line pairs/mm sample at __pixels/mm

Answer 59

5

Question 60

An S value of 200 indicates that the IP received about __mR

Answer 60

1

Question 61

What refers to a gradual increase in patient exposure over time due to wide exposure latitude of digital processing

Answer 61

Dose creep

Question 62

What does DAP mean, and what does it do

Answer 62

Dose area product, measures patient’s entrance skin dose

Question 63

Where is the DAP located

Answer 63

Collimator box

Question 64

What does the DAP not take into account

Answer 64

SID

Question 65

What resolution monitors are used for CT

Answer 65

1K

Question 66

What resolution monitors are used for general exams

Answer 66

2K 3K

Question 67

What resolution monitors are used for mammography

Answer 67

5K

Question 68

What is the purpose of DICOM

Answer 68

Standardized public format and protocol for communicating imaging files

Question 69

What is a film digitizer

Answer 69

A device that converts an analog film image into a digital computer image

Question 70

What is a hard copy of an image

Answer 70

Images produced on film using a laser printer

Question 71

What is a soft copy image

Answer 71

Images viewed on a flat screen monitor

Question 72

What is veiling glare

Answer 72

Light from inside the monitor that floods the retinas

Question 73

What does the conductor layer of the IP do

Answer 73

Absorbs light to increase sharpness

Question 74

What does the light shield layer of the IP do

Answer 74

Prevents light from erasing data

Question 75

What does the backing layer of the IP do

Answer 75

Lined with lead to reduce backscatter

Question 76

What is the factor that makes DR IR’s respond faster

Answer 76

Increases kvp

Question 77

What imaging system has the best contrast resolution

Answer 77

DR

Question 78

What is fast scan with digital imaging

Answer 78

Reading of the DEL’s