Rad 106 Final

Front 1

A radiographer can best minimize the amount of scatter radiation reaching the image receptor by restricting the beam. True or false?

Back 1

True

Front 2

The principal factors that affect the amount of scatter produced are mas and the type of irradiated material. True or false?

Back 2

False

Front 3

When kilovoltage is increased with no other changes in technical factors, fewer scattered photons will result. True or false?

Back 3

false

Front 4

scattered photons from compton interactions are of no use in demonstrating radiographic structures of interest. True or false?

Back 4

True

Front 5

Image quality is improved when scatter reaching the image receptor is reduced. True or false?

Back 5

True

Front 6

Bone absorbs More radiation and procedures more scatter than soft tissue. True or false?

Back 6

False

Front 7

soft tissue absorbs More radiation and procedures more scatter than bone. True or false?

Back 7

false

Front 8

Lead masks may serve as beam restrictors. True or false?

Back 8

True

Front 9

scatter radiation in radiography is produced during?

Back 9

Compton interactions

Front 10

scattered photons will?

Back 10

-impair image quality

- add density to image receptor exposure

- not be considered part of the useful beam

Front 11

A radiographer can best reduce the amount of scatter radiation from reaching the receptor by?

Back 11

-collimating

-beam restriction

- utilizing a grid

Front 12

which of the following is placed between the patient and the image receptor to absorb scatter radiation?

Back 12

radiographic grid

Front 13

A key factor that affects the amount of scatter produced is?

Back 13

Kilovoltage

Front 14

As the kilovoltage increases, the percentage of x-rays that undergo _______interactions will increase.

Back 14

Compton

Front 15

As the kilovoltage increases, the percentage of photons that undergo a ______interaction will decrease.

Back 15

photoelectric

Front 16

If an increase in kilovoltage is accompanied by a reduction in mas, to maintain the same exact dose the overall result will be?

Back 16

a decrease in the amount of scatter produced.

Front 17

As the volume of irradiated tissue ____ , the amount of scatter produced____.

Back 17

increases; increases

Front 18

Tue volume of the irradiated tissue increases as?

Back 18

field size and patient thickness increase.

Front 19

The _____ the atomic number of the irradiated material, the ______ the number of photoelectric absorption interactions that occur.

Back 19

higher ; higher

Front 20

The____ the atomic number of the irradiated material, the____ the number of photoelectric absorption interactions will be, and the____ the scatter produced.

Back 20

higher; higher; less

Front 21

When a beam restricting device is used to limit field size, technical factors may need to____ to compensate for the charge in image receptor exposure.

Back 21

be increased

Front 22

All of the following are considered beam restricting devices except?

Back 22

beam filter

Front 23

Penumbra is ___ when the beam restrictor scatter is at a ___ distance from the port.

Back 23

reduced; increased

Front 24

an effective method for reducing scatter radiation production is the?

Back 24

15% rule of kvp change

Front 25

The shutter of a collimator?

Back 25

regulate field size, reduce penumbra, reduce stem radiation

Front 26

When collimating down from a 14x17 field size to a 8x10 field size:

Back 26

mas must be increased to maintain radiograohic image density.

Front 27

The collimation assembly of a radiographic unit?

Back 27

employs an upper and lower set of shutter blades

Front 28

Placing a lead blocker adjacent to an obese patient's anatomy during a lateral lumbar spine radiograph?

Back 28

will improve image quality

Front 29

The incident beam is significatly altered as it passes through the patient. true or false?

Back 29

true

Front 30

the beam emitted from the patient contains diagnostic information. true or false?

Back 30

true

Front 31

subject distortion occurs naturally. true or false?

Back 31

true

Front 32

subject distortion can be reduced by accurately positioning the patient. true or false?

Back 32

true

Front 33

the patient has an impact on all the properties that affect the radiograoh quality. true or false?

Back 33

true

Front 34

the relationship between image receptor exposure and the patient is termed subject density. true or false?

Back 34

true

Front 35

the relationship between radiographic contrast and the patient is termed subject contrast. true or false?

Back 35

true

Front 36

The ____ the body part, the ____ the attenuation.

Back 36

thicker;greater

Front 37

which of the folloeing elements would attenuate a greater percentage of the xray beam?

Back 37

calcium

Front 38

Bone produces less image receptor ___ because it attenuates the xray beam more than soft tissue does.

Back 38

density

Front 39

Foe the same exposure intensity, air produces?

Back 39

greater exposure intensity to the receptor than other materials.

Front 40

Which of the following is the least attenuator of the xray beam?

Back 40

pneumonated lung air (air filled)

Front 41

As subject density ____, image receptor exposure ____.

Back 41

increases; decreases

Front 42

The degree if differential absorption is referred to as?

Back 42

subject contrast

Front 43

The recorded detail of a structure is dependant on?

Back 43

- its position within the body

- the okacement of the body in the relationship to the film

- the size of the part

Front 44

Distortion is the misrepresentation of the ____ of an object.

Back 44

- length

- shape

- width

Front 45

The primary source of radiation exposure for occupational persinnel is due to?

Back 45

Compton scatter

Front 46

Clinically speaking from a diagnostic viewpoint, the only useful radiation exposure is that radiation?

Back 46

detected by the receptor.

Front 47

digital radiography replaces?

Back 47

conventional film

Front 48

which type of system uses a two part process to convert incoming x ray photons to an electronic digital signal?

Back 48

indirect acquisition

Front 49

during the two part acquisition system, a ____ converts xray photons to light.

Back 49

scintillator

Front 50

During the two-part acquisition system, a ___ converts light into an electronic digital signal.

Back 50

photodetector

Front 51

An imaging plate includes a ____ layer.

Back 51

-phosphor

-protective

- conductor

Front 52

A charged couple device is a photo detecor capable of converting?

Back 52

visible light to an electrical signal

Front 53

The latent image will lose about 25% of it's energy in?

Back 53

8 hours

Front 54

The latent image created by CR is processed by a?

Back 54

image reader device.

Front 55

When the CR imaging plate is scanned, the phosphors of the latent image release energy in the form of?

Back 55

light

Front 56

The histogram generated from the image data allows the digital system?

Back 56

- to find the useful areas on the IP

- to create a graph based on the anatomy selected

Front 57

A CR artifact caused by insufficient mAs (low exposure) is?

Back 57

quantum mottle

Front 58

The smallest part of a digital image describes:

Back 58

pixel

Front 59

As pixel size decreases, resolution ____.

Back 59

increases.

Front 60

The window level controls _______.

Back 60

image brightness

Front 61

All of the following are quality factors for digital imaging, except?

Back 61

distortion

Front 62

As the sensitivity number (s) increases, the image becomes?

Back 62

underexposed

Front 63

Detective Quantum Efficiency (DQE) is a measure of the sensitivity and accuracy by which the image receptor converts the incoming data to the output device. True or false?

Back 63

True

Front 64

Bit depth is controlling factor of ____ in digital radiography.

Back 64

density

Front 65

The range of possible shades of gray as determined by the manufacturer of a digital imaging system is called?

Back 65

Bit depth

Front 66

Digital imaging plates are more radiosensitive and conventional film. true or false?

Back 66

true

Front 67

Computed radiography utilizes direct acquisition. True or false?

Back 67

False

Front 68

Which of the following is more desirable for image quality?

Back 68

High SNR

Front 69

Digital radiography utilizes the same xray tube as conventional radiography. true or false?

Back 69

true

Front 70

Each cell of an image matrix is called what?

Back 70

a pixel

Front 71

What is the purpose o the conductor layer of the IP?

Back 71

Protect the IP from electrostatic shock

Front 72

As the exposure index number increases, the image becomes:

Back 72

underexposed

Front 73

In digital imaging, the light that comes off the imaging plate when being scanned by a laser proportional to the xray exposure received by the phosphor. true of false?

Back 73

true

Front 74

Which of the following is referred to as the active layer of the CR cassette?

Back 74

Phosphor layer.

Front 75

Direct digital imaging systems use imaging plates. True or false?

Back 75

True

Front 76

In a digital imaging plate a fill factor of 80% indicates that the pixel is _____% pixel detector and _____% image conversion electronics.

Back 76

80 and 20

Front 77

Digital radiography (DR) is characterized by?

Back 77

the use of reusable receptors.

Front 78

Each binary number is called a?

Back 78

bit

Front 79

An eight-bit word is called a?

Back 79

byte

Front 80

CR systems acquire clinical information by?

Back 80

laser scanning a PSP plate

Front 81

Resolution is controlled by ___ size.

Back 81

pixel

Front 82

Each pixel in a digital display matrix is located according to its?

Back 82

electronic address

Front 83

A matrix of size 2048x1536 would have ____ pixels.

Back 83

3,145,728

Front 84

If the digital FOV is 1024 and the display matrix is 512, the pixel size would be?

Back 84

2

Front 85

In digital image processing, the digital data set is arranged into a histograph distribution in order to determine the?

Back 85

- exposure index

- values of interest (VOI)

Front 86

The number of shades of gray; ranges from 8 bits to 32 bits. A grayscale bit depth 8-32 equals a range of 1-4 byte of storage that would be required per pixel in the image matrix. A grayscale bit depth of 12 produces 212 gray levels. This represents 4,096 different shades of gray.

Back 86

Gray scale bit depth

Front 87

Typically inside a cassette; used in computed radiography.

Back 87

photostimulable storage phosphor imaging plate

Front 88

The physical distance between pixels; generally measured from center to center.

Back 88

pixel pitch

Front 89

Applied to the data that has the standard contrast for that exam to give the desired image contrast for display.

Back 89

look-up table (LUT)

Front 90

Two-part process involving a scintillator and a photo detector.

Back 90

indirect conversion

Front 91

A point processing operation that changes the contrast and brightness of the image on the monitor.

Back 91

windowing

Front 92

Direct conversion of incoming xray photons to an electronic signal.

Back 92

direct conversion

Front 93

Correction of an exposure that is outside the range from underexposure or overexposure by shifting the histogram to the correct area.

Back 93

rescaling

Front 94

Imaging systems that replace traditional film with a PSP and cassette; the plate must be processed in an image reader system.

Back 94

digital radiography (DR)

Front 95

Imaging systems that replace traditional film with a reusable detector; the detector and reader are a permanent part of a table or wall unit, and therefore a cassette is not needed.

Back 95

digital radiography (CR)

Front 96

Noise on a digital image is the summation of inherent electron system noise and quantum mottle noise. Of these two, the radiographer can improve the noise on an image by?

Back 96

increasing the exposure technique

Front 97

An S value of 200 represents a?

Back 97

exposure to the IP of 1 mR

Front 98

When using CR technology, it is important to remember that?

Back 98

- the IP is extra sensitive to exposure after the inital xray exposure

-the IP will lose about 25% of its signal in 8 hours if not processed

-the IP is very sensitive to scatter, making grids very important

Front 99

The size of a digital file size is determined by the?

Back 99

-bit depth

-pixel size

-matrix

Front 100

In CR technology, preprocessing of data includes?

Back 100

-histogram analysis

-gray scale analysis

-exposure data recognition (EDR)

Front 101

What compound used in flat panel radiography receptors to convert in coming xrays directly into an electrical signal?

Back 101

amorphous selenium

Front 102

Which of these matrix sizes will have the smallest pixels?

Back 102

2048x2048

Front 103

Which of these matrices will have the best spatial resolution?

Back 103

2048x2048

Front 104

Increasing the field of view will have what effect on the pixel size?

Back 104

decreased pixel size

Front 105

which of these technologists errors is most likely to result in incorrect histogram rescaling?

Back 105

processing a knee radiograph as a chest

Front 106

durinf the two part acquisition system, a ____ converts xray photons to light.

Back 106

scintillator

Front 107

during the two part acquisition system, a ____ converts light into an electronic digitwl signal.

Back 107

photo detector

Front 108

an imaging plate includes a ____ layer

Back 108

-phosphor layer

- protective layer

- conductor layer

Front 109

A charged couple device is a photo detector capable of converting?

Back 109

visible light to an electrical signal.

Front 110

The latent image will lose 25% of its energy in?

Back 110

8 hours

Front 111

The latent image created by CR is processed by an?

Back 111

image reader device.

Front 112

When the CR imaging plate is scanned, the phosphors of the latent image release energy in the format of?

Back 112

light

Front 113

The histogram genersted from the imsge data allows the digital system?

Back 113

- to find the useful area (densities) on the IP

- to create a graph based on the anatomy selected

Front 114

A CR artifact caused by unsufficient mAs (low exposure) is?

Back 114

quantum mottle

Front 115

The smallest part of a digital image describes:

Back 115

pixel

Front 116

As oixel size decreases, resolution?

Back 116

increases

Front 117

The window level controls?

Back 117

image brightness

Front 118

All of the following are quality factors for digital imaging, except:

Back 118

distortion

Front 119

As the sensitivity number (s) increases, the image becomes:

Back 119

underexposed

Front 120

Detective quantum efficiency (DQE) is a measure of the sensitivity and accuracy by which the image receptor converts the incoming data to the output device. true or false?

Back 120

true

Front 121

Bit depth is a controlling factor of ___ in digital radiography.

Back 121

Density

Front 122

The range of possible shades of gray as determined by the manufacturer of a digital imaging system is called:

Back 122

bit depth

Front 123

Digital plates are more radiosensitive and conventional film. tru of false?

Back 123

true

Front 124

Computed radiography utilizes direct aquisition. true or false?

Back 124

false

Front 125

Which of the following is more desirable for image quality?

Back 125

high snr

Front 126

digital radiography utilizes the same xray tube as conventionao radiography. true or false?

Back 126

true

Front 127

each cell of an image matrix is called what?

Back 127

a pixel