Image Acquisition & Evaluation

Front 1

Misalignment of the tube-part-IR relationship in

Back 1

Shape distortion

Front 2

In digital imaging, brightness is controlled by

Back 2

2. Monitor functions

3. Postprocessing functions

Front 3

In electronic imaging, as digital image matrix size increases

Back 3

Pixel size decreases

Front 4

An algorithm, as used in x-ray imaging is an

Back 4

Series of variable instructions

Front 5

The chest radiograph shown in Figure 4-1 demonstrates

Back 5

Aliasing artifact

Front 6

The intensity of ionizing radiation decreases as

Back 6

Distance from the source of radiation increases

Front 7

Grid interspace material can be made of

Back 7

2. Aluminum

3. Plastic fiber

Front 8

The reduction in x-ray photon intensity as the photon passes through material is termed

Back 8

Attenuation

Front 9

Which of the lines indicated in Figure 4-2 represents the dynamic range offered by commuted radiography/digital radiography (CR/DR)?

Back 9

Line A is representative of CR/DR

Front 10

An increase in kilovoltage will have which of the following effects in digital imaging?

Back 10

1. More scattered radiation will be produced

2. The exposure rate will increase

Front 11

The x-ray tube used in CT must be capable of

Back 11

1. High-speed rotation

2. Short pulsed exposures

3. Withstanding millions of heat units

Front 12

What is the correct critique of the CR image shown in Figure 4-3?

Back 12

Double exposure

Front 13

If a lateral projection of the chest is being performed on an asthenic patient and the outer photocells are selected, what is likely to be the outcome?

Back 13

Decreased IR exposure

Front 14

Which of the following groups of exposure factors will produce the greatest receptor exposure?

Back 14

400 mA, 70 ms

Front 15

The component of a CR image plate (IP) that records the radiologic image is the

Back 15

Photostimulable phosphor

Front 16

An x-ray image of the ankle was made at 40 SID, 200 mA, 50 ms, 70 kV, 0.6-mm focal spot, and minimal OID. Which of the following modifications would result in the greatest increase in magnification?

Back 16

4 '' OID

Front 17

The radiation dose received by the digital detector for each image is indicated by the

Back 17

Exposure indicator

Front 18

HVL is affected by the amount of

Back 18

1. kVp

2. Beam filtration

Front 19

The luminescent light emitted by the PSP is transformed into the image seen on the CRT by the

Back 19

ADC

Front 20

The lateral coccyx image shown in Figure 4-4 was made using AEC but is overexposed. This is most likely a result of

Back 20

Incorrect centering of part

Front 21

Which of the following units are used to express exposure?

Back 21

1. Line-spread function

2. Line pairs per millimeter

Front 22

The term windowing describe the practice of

Back 22

Changing the image brightness and/or contrast scale

Front 23

Foreshortening can be caused by

Back 23

The radiographic object being placed at an angle to the IR

Front 24

Acceptable methods of minimizing motion unsharpness is

Back 24

1. Suspended respiration

2. Short exposure time

3. Patient instruction

Front 25

Using fixed milliampere-seconds and variable kilovoltage technical factors, each centimeter increase in patient thickness requires what adjustment in kilovoltage

Back 25

Increase 2 kV

Front 26

Unopened boxes of radiographic film should be stored away from radiation and

Back 26

In the vertical position

Front 27

Potential digital image post processing tasks include

Back 27

2. Annotation

3. Inversion/reversal

Front 28

Factors that contribute to film fog include

Back 28

1. The age of the film

2. Excessive exposure to safelight

3. Processor chemistry

Front 29

X-ray photon energy is inversely related to

Back 29

1. Photon wavelength

Front 30

Which of the radiographs shown in Figure 4-5 most likely required the greater exposure?

Back 30

Image B

Front 31

Characteristics of DR imaging include

Back 31

1. Solid-state detector receptor include

2. A direct-capture imaging system

3. Immediate image display

Front 32

Compared with a low-ratio grid, a high-ratio grid will

Back 32

2. Absorb more scattered radiation

3. Absorb more primary radiation

Front 33

A decrease in kilovoltage will result in

Back 33

2. A decrease in photon energy

3. A decrease in receptor exposure

Front 34

What is the correct critique of the CR image shown in Figure 4-6?

Back 34

Inverted IP

Front 35

To be suitable for used in an image intensifier's input screen, a phosphor should have which of the following characteristics?

Back 35

1. High conversion efficiency

2. High x-ray absorption

3. High atomic number

Front 36

Resolution in CR increases as

Back 36

1. Laser beam size decreases

3. PSP crystal size decreases

Front 37

What pixel size has 512 x 512 matrix with 20-cm filed of view (FOV)?

Back 37

0.40mm/pixel

Front 38

In radiography of a large abdomen, which of the following are effective ways to to minimize the amount of scattered radiation reaching the image receptor (IR)?

Back 38

1. Use of close collimation

Front 39

Which of the following factors contributes to the efficient performance of a grid?

Back 39

1. Grid ration

2. Number of lead strips per inch

3. Amount of scatter transmitted through grid

Front 40

The changes between the images shown in Figure 4-7 represent changes made to

Back 40

Window width

Front 41

All the following affect the exposure rate of the primary beam except

Back 41

Field size

Front 42

Which of the following terms is used to describe unsharp edges of tiny radiographic details?

Back 42

Blur

Front 43

Image contrast, in screen-film imaging, is a result of

Back 43

1. Differential tissue absorption

2. Atomic number of tissue being traversed

Front 44

What grid ratio is represented in Figure 4-8?

Back 44

10:1

Front 45

A 5'' object to be radiographed at a 44'' in SID lies 6 inches from the IR. What will be the image width?

Back 45

5.7 in

Front 46

In comparison with 60 kV, 80 kV (in analog/screen film imaging) will

Back 46

1. Permit greater exposure latitude

2. Produce more scattered radiation

Front 47

The term pixel is associated with all of the following except

Back 47

How much of the part is included in the matrix

Front 48

Geometric blur can be evaluated using all the following devices except

Back 48

Penetrometer

Front 49

Causes of grid cutoff, when using focused reciprocating grids, include the following?

Back 49

Inadequate SID

Front 50

The tiny increased brightness, dropout artifacts seen in the proximal portion of the CR image of the radius shown in Figure 4-9 are representative of

Back 50

Dust/dirt on the PSP

Front 51

Using a short (25-30in) SID with a large (14x17 in) IR is likely to

Back 51

Increase the anode heel effect

Front 52

Which of the following groups of factors would produce the least radiographic density in analog/screen film imaging?

Back 52

100 mA, 0.020 second, 80 kV, 200-speed screens

Front 53

Chemical fog on radiographic film image may be attributed to

Back 53

1. Excessive developer temperature

2. Oxidized developer

3. Excessive replenishment

Front 54

Because of the anode heel effect, the intensity of the x-ray beam is greatest along the

Back 54

Cathode end of the beam

Front 55

The differences between CR and DR include

Back 55

1. CR uses IPs

Front 56

The term voxel is associated with all of the following except

Back 56

Field of view

Front 57

Using a 48'' SID, how much OID must be introduced to magnify an object two times?

Back 57

24'' OID

Front 58

A particular radiograph was produced using 12 mAs and 85 kV with a 16:1 grid. The radiograph is to be repeated using an 8:1 ratio grid. What should be the new milliampere-seconds value?

Back 58

8

Front 59

The main difference between the direct capture and indirect capture DR is that

Back 59

Direct capture/conversion has no scintillator

Front 60

Analog-to-digital conversion is required in the following imaging system

Back 60

CR

Front 61

The photostimulable phosphor (PSP) plates used in CR are constructed in layers that include

Back 61

1. Light shield layer

2. Support layer

3. Electroconductive layer

Front 62

For the same FOV, spatial resolution will be improved using

Back 62

A larger matrix

Front 63

Which of the following are methods of limiting the production of scattered radiation?

Back 63

2. Using the prone position for abdominal exams

3. Restricting the field size to the smallest practical size

Front 64

Two screen-film images of the skull are shown in Figure 4-10. Which of the following best describes their different appearance?

Back 64

Image A demonstrates higher contrast

Front 65

The absorption of useful radiation by a grid is called

Back 65

Grid cutoff

Front 66

Which of the images in Figure 4-11 has the largest matrix size?

Back 66

Image #4

Front 67

Types of shape distortion include

Back 67

2. Elongation

3. Foreshortening

Front 68

For the same FOV, as the matrix size increases

Back 68

1. Spatial resolution increases

2. Image quality increases

3. Pixel size decreases

Front 69

In digital imaging, as the size of the image matrix increases

Back 69

2. Pixel size decreases

3. Spatial resolution increases

Front 70

All of the following are related to spatial resolution except

Back 70

Milliamperage

Front 71

A satisfactory radiograph was made using a 36'' SID, 12 mAs, and a 12:1 grid. If the exam will be repeated at a distance of 42'' and using a 5:1 grid, what should be the new milliampere-seconds value to maintain the original receptor exposure?

Back 71

6.5

Front 72

Of the following groups of exposure factors, which will produce the most receptor exposure?

Back 72

200 mA, 60 ms, 36'' SID

Front 73

Which of the following groups of analog/screen film exposure factors will produce the shortest scale of contrast?

Back 73

500 mA, 0.03 second, 70 kV, 8:1

Front 74

All of the following statements regarding digital imaging are true, except

Back 74

Brightness is related to IR exposure

Front 75

In digital imaging, kV selection has an effect on

Back 75

1. Photon energy

2. Penetration

Front 76

Which of the following factors influences the production of scattered radiation?

Back 76

1. Kilovoltage level

2. Tissue density

3. Size of field

Front 77

Exposure factors of 2 mAs and 75 kV were used for a particular part. Which of the following changes would result in twice the exposure to the image receptor?

Back 77

4 mAs

Front 78

Factors impacting spatial resolution include

Back 78

1. Focal spot size

2. Subject motion

3. SOD

Front 79

Which of the following are tested as part of a quality assurance (QA) program?

Back 79

1. Beam alignment

2. Reproducibility

3. Linearity

Front 80

Focal-spot blur is greatest

Back 80

Toward the cathode end of the x-ray beam

Front 81

How are mAs and patient dose related?

Back 81

mAs and patient dose are directly proportional

Front 82

Image plate front material can be made of which of the following?

Back 82

1. Carbon fiber

2. Magnesium

Front 83

Which of the following pathologic conditions would require a decrease in exposure factors?

Back 83

Emphysema

Front 84

An exposure was made at a 36'' SID using 300 mA, a 30ms exposure, and 80 kV and an 8:1 grid. It is desired to repeat the radiograph using a 40'' SID and 70 kV. With all other factors remaining constant, what new exposure time will be required?

Back 84

0.07 second

Front 85

Practice that enable the radiographer to reduce the exposure time required for a particular image include

Back 85

1. Use of a higher milliamperage

2. Use of a higher kilovoltage

Front 86

If 400 mA, 10 ms, and 90 kV were used for a particular exposure using three-phase, 12-pulse equipment, which of the following exposure changes would be most appropriate for use on single-phase equipment to produce a similar image?

Back 86

Use 0.02 second

Front 87

Which of the following materials may be used as grid interspace material?

Back 87

2. Plastic

3. Aluminum

Front 88

The radiograph shown in Figure 4-12 demonstrates an example of

Back 88

Exposure artifact

Front 89

Exposure-type artifacts include

Back 89

1. Double exposure

2. Motion

Front 90

An increase in the kilovoltage applied to the x-ray tube increases the

Back 90

2. Exposure rate

Front 91

Which of the following statements about histograms are true?

Back 91

1. A histogram illustrates pixel value distribution

2. There is a default histogram for each/different body parts

3. A histogram is representative of the i mage grayscale

Front 92

Which of the following is the correct order of radiographic film processing?

Back 92

Developer, fixer, wash, dry

Front 93

If the radiographer is unable to achieve a short OID because of the structure of the body part or patient condition, which of the following adjustments can be made to minimize magnification distortion?

Back 93

A longer SID should be used

Front 94

The exposure factors used for a particular non grid x-ray image were 300 mA, 4 ms, and 90 kV. Another image, using an 8:1 grid, is requested. Which of the following groups of factors is most appropriate?

Back 94

400 mA, 12 ms, 90 kV

Front 95

The PA chest image shown in Figure 4-13 exhibits which of the following qualities?

Back 95

1. Adequate penetration of the heart

2. Long-scale contrast

3. Adequate inspiration

Front 96

Exposure rate will decrease with an increase in

Back 96

SID

Front 97

Which of the following pathologic conditions probably will require a decrease in exposure factors?

Back 97

Osteoporosis

Front 98

Diagnostic x-rays are generally associated with

Back 98

High frequency and short wavelength

Front 99

A screen-film image exhibiting insufficient density might be attributed to

Back 99

1. Inadequate kilovoltage

3. Grid cutoff

Front 100

Decreasing field size from 14 x 17 in to 8 x 10 inch, with no other changes, will

Back 100

Decrease the amount of scattered radiation generated within the part

Front 101

Which of the following devices is used to overcome severe variation in patient anatomy or tissue density, providing more uniform receptor exposure?

Back 101

Compensating filter

Front 102

What are the effects of scattered radiation on a radiographic image?

Back 102

1. It produces fog

Front 103

Which of the following groups of exposure factors would be most appropriate to control involuntary motion?

Back 103

600 mA, 0.02 second

Front 104

Spatial resolution/detail can be improved by decreasing

Back 104

2. OID

3. Patient/part motion

Front 105

The functions of the developer in film processing is to

Back 105

2. Change the exposed silver bromide crystals to black metallic silver

Front 106

In digital imaging, mAs selection has an effect on

Back 106

1. Receptor exposure

2. Patient dose

Front 107

The x-ray image seen in Figure 4-14 is most likely the result of

Back 107

Too low mAs factors

Front 108

Which of the following affects both the quantity and the quality of the primary beam?

Back 108

1. Half-value layer (HVL)

2. Kilovoltage (kV)

Front 109

In which of the following ways dose SID affect spatial resolution?

Back 109

Spatial resolution is directly related to SID

Front 110

Which of the following would be useful for an exam of a patient suffering from Parkinson's disease?

Back 110

1. Short exposure time

Front 111

Underexposure of an SF radiograph can be used by all the following except insufficient

Back 111

SID

Front 112

If a duration of 0.05 second was selected for particular exposure, what milliamperage would be necessary to produce 30 mAs?

Back 112

600

Front 113

An anteropostior (AP) projection of the fetus was made using 300 mA, 0.03 second, 76 kV, 40'' SID, 1.20-mm focal spot, and a 400 speed screen-film system. With all other factors remaining constant, which of the following exposure times would be required to maintain correct IR exposure at a 44'' SID using 500 mA?

Back 113

22 ms

Front 114

An AP radiograph of the femur was made using 300 mA, 30 ms, 76 kV, 40'' SID, 1.2-mm focal spot. With all other factors remaining constant, which of the following exposure times would be required to maintain correct IR exposure using 87 kV and the addition of a 12:1 grid?

Back 114

75 ms

Front 115

Which of the following statements regarding dual x-ray absorptiometry are true?

Back 115

1. Radiation dose is low

3. Photon attenuation by bone is calculated

Front 116

In a posteroanterior (PA) projection of the chest being used for cardiac evaluation, the heart measures 14.7 cm between its widest points. If the magnification factor is known to be 1.2, what is the actual diameter of the heart?

Back 116

12.25 cm

Front 117

Bone densitometry is often performed to

Back 117

1. Measure degree of bone (de) mineralization

2. Evaluate the results of osteoporosis treatment/therapy

Front 118

The differences between CR and DR include

Back 118

1. DR images are displayed immediately

2. DR has higher DQE and lower patient dose

Front 119

Which of the following error is illustrated in Figure 4-15?

Back 119

X-ray tube not centered to grid

Front 120

The process of "windowing" of digital images determines the image

Back 120

Contrast

Front 121

What is the purpose of the thin layer of lead that is often located in the rear portion of an IP?

Back 121

To prevent scattered radiation fog

Front 122

The purpose of the electroconductive layer of a CR PSP plate is to

Back 122

Facilitate transpiration through the scanner/reader

Front 123

Which of the following combinations is most likely to be associated with quantum mottle?

Back 123

Decreased milliampere-seconds, increased kilovoltage

Front 124

What pixel size has 2,048 x 2,048 matrix with a 60-cm FOV?

Back 124

0.3 mm

Front 125

As window level increases

Back 125

Brightness increases

Front 126

Which of the following matrix sizes is most likely to produce the best image resolution?

Back 126

2,048 x 2,048

Front 127

The device shown in Figure 4-16 is used for

Back 127

Mammographic QA testing

Front 128

Factors that determine spatial resolution in digital imaging include

Back 128

1. Part motion

2. Geometric factors

3. Size of focal spot

Front 129

Examples of healthcare information include

Back 129

1. HIS

2. RIS

3. PACS

Front 130

The exposure factors of 400 mA, 17 ms, and 82 kV produce a milliampere-seconds value of

Back 130

6.8

Front 131

All the following statements regarding CR IP's are true except

Back 131

IPs must exclude all white light

Front 132

The radiographic accessory used to measure the thickness of body parts in order to determine optimal selection of exposure factors is the

Back 132

Caliper

Front 133

The x-ray image sent on the computer display monitor is an

Back 133

Analog image

Front 134

Modifications to the degree of digital image brightness can be made by adjustments to

Back 134

2. Monitor controls

3. Window level post processing

Front 135

For which of the following exams can the anode heel effect be an important consideration?

Back 135

1. Lateral thoracic spine

2. AP femur

Front 136

All the following have an impact on radiographic contrast except

Back 136

Focal spot size

Front 137

A radiograph made with a parallel grid demonstrates decreased receptor exposure on its lateral edges. This is most likely due to

Back 137

Decreased SID

Front 138

What is the correct critique of the CR image shown in Figure 4-17?

Back 138

Grid centering error

Front 139

A particular milliampere-seconds value, regardless of the combination of milliamperes and time, will reproduce the same receptor exposure. This is a statement of

Back 139

Reciprocity law

Front 140

OID is related to spatial resolution in which of the following ways?

Back 140

Spatial resolution is inversely related to OID

Front 141

If 300 mA has been selected for a particular exposure, what exposure time would be required to produce 6 mAs?

Back 141

20 ms

Front 142

In digital imaging, as DEL size decrease

Back 142

Spatial resolution increases

Front 143

An increase in kilovoltage will serve to

Back 143

Increase photon energy

Front 144

The functions of automatic beam limitation devices include

Back 144

1. Reducing the production of scattered radiation

Front 145

Spatial resolution is inversely related to

Back 145

2. OID

3. Part motion

Front 146

Of the following groups of SF exposure factors, which will produce the shortest scale of radiographic contrast?

Back 146

500 mA, 0.040 second, 70 kV

Front 147

The artifact seen in Figure 4-18 represents

Back 147

CR processing artifact

Front 148

Magnification fluoroscopy is accomplished by

Back 148

1. Moving the image intensifier focal point further from the output phosphor

2. Selecting a smaller portion of the input phosphor

Front 149

Figure 4-19 is representative of

Back 149

Anode heel effect

Front 150

Of the following groups of technical factors, which will produce the greatest radiographic receptor exposure?

Back 150

10 mAs, 74 kV, 36'' SID

Front 151

Which of the following requires two exposures to evaluate focal spot accuracy?

Back 151

Slit camera

Front 152

Focusing distance is associated with which of the following?

Back 152

Grids

Front 153

The processing algorithm represents the

Back 153

Anatomical part and projection

Front 154

The relationship between the height of a grid's lead strips and the distance between them is referred to as grid

Back 154

Ratio

Front 155

Greater latitude in analog/screen-film imaging is available to the radiographer in which of the following circumstances?

Back 155

1. Using high kV technical factor

2. Using low-ratio grid

Front 156

Characteristics of high-ratio focused grids, compared with lower-ratio grids, include which of the following?

Back 156

2. They are more efficient in collecting SR

3. They absorb more of the useful beam

Front 157

Factors that can affect histogram appearance include

Back 157

1. Beam restriction

2. Centering erros

3. Incorrect SID

Front 158

Figure 4-20 was made using screen-film technique. The area of blurriness seen in the upper part of the radiograph shown is most likely due to

Back 158

Poor screen-film contact

Front 159

Changes in milliampere-seconds can affect all the following except

Back 159

Spatial resolution

Front 160

Low kilovoltage exposure factors usually are indicated for radiographic exams using

Back 160

1. Water-soluble, iodinated media

2. A negative contrast agent

Front 161

Which of the following exams might require the use of 70 kV?

Back 161

1. AP abdomen

Front 162

Which of the following are associated with magnification fluoroscopy?

Back 162

1. Increased mA

2. Smaller portion of the input phosphor is used

Front 163

A lateral SF projection of the lumbar spine was made using 200 mA, 1.0-second exposure, and 90 kV. If the exposure factors were changed to 200 mA, 0.5 second, and 104 kV, there would be an obvious change in which of the following?

Back 163

2. Scale of radiographic contrast

Front 164

Subject/object unsharpness can result from all of the following except when

Back 164

Anatomic objects of interest are in the path of the CR

Front 165

Brightness and contrast resolution in digital imaging can be influenced by

Back 165

1. Window level (WL)

2. Window width (WW)

3. Look-up table (LUT)

Front 166

What feature is used to display RIS information on current patients?

Back 166

Modality work list

Front 167

A decrease from 200 to 100 mA will result in a decrease in which of the following?

Back 167

2. Exposure rate

3. Beam intensity

Front 168

The radiograph shown in Figure 4-21 illustrates incorrect use of

Back 168

Grid

Front 169

The effect described as differential absorption is

Back 169

1. Responsible for radiographic contrast

2. A result of attenuating characteristics of tissue

3. Minimized by the use of a high peak kilovoltage

Front 170

A satisfactory radiograph of the abdomen was made at a 38'' SID using 400 mA, 60-ms exposure, and 80 kV. If the distance is changed to 42'', what new exposure time would be required?

Back 170

73 ms

Front 171

Which of the following are associated with subject contrast?

Back 171

1. Patient thickness

2. Tissue density

3. Kilovoltage

Front 172

Typical patient demographic and examination info includes

Back 172

1. Type of exam

2. Accession #

3. Date and time of exam

Front 173

For which of the following exams might the use of a grid not be necessary in an adult patient?

Back 173

Knee

Front 174

The quantity of scattered radiation reaching the IR can be reduced through the use of

Back 174

2. An air gap

3. A stationary grid

Front 175

Why is a very short exposure time essential in chest radiography?

Back 175

To minimize involuntary motion

Front 176

The interaction between x-ray photons and matter illustrated in Figure 4-22 is most likely to be associated with

Back 176

1. High kilovoltage

Front 177

Beam attenuation characteristics, or density values, in CT are expressed as

Back 177

1. Hounsfield units

2. CT numbers

Front 178

If an IR exposed using a 12:1 grid exhibits loss of signal at its lateral edges, it is probably because the

Back 178

SID was too great

Front 179

Which of the following is characteristics of a 5:1 grid?

Back 179

1. It allows some positioning latitude

Front 180

How is SID related to exposure rate and image receptor exposure?

Back 180

As SID increases, exposure rate decreases and receptor exposure decreases

Front 181

An x-ray exposure of a particular part is made and restricted to a 14 x 17 '' field size. The same exposure is repeated, but the x-ray beam is restricted to a 4 x 4 '' field. Compared with the first image, the second image is likely to

Back 181

1. Generate less scattered radiation

2. Require increased exposure factors

Front 182

In digital imaging , TFT DEL size is related to

Back 182

Spatial resolution

Front 183

Which of the following pathologic conditions would require an increase in exposure factors?

Back 183

Ascites

Front 184

Factors that determine spatial resolution in digital imaging include

Back 184

1. Focal-spot size

2. SID

3. DEL size

Front 185

Which of the following analog/screen-film technical changes would best serve to remedy the effect of very dissimilar tissue densities?

Back 185

High kilovoltage exposure factors

Front 186

A QA program serves to

Back 186

1. Keep patient dose to a minimum

2. Keep radiographic quality consistent

3. Ensure equipment efficiency

Front 187

One line pair is described as

Back 187

One black line on a light background an d on interspace of the same width

Front 188

Any images obtained using dual x-ray absorptiometry (DXA) bone densitometry

Back 188

1. Are used to evaluate accuracy of the region of interest (ROI)

Front 189

Foreshortening of an anatomic structure means that

Back 189

It is projected on the IR smaller than its actual size

Front 190

Digital radiographic imaging equipment provides a number of functions for optimization of image quality, include

Back 190

1. Exposure data recognition

2. Automatic rescaling

Front 191

A SF x-ray image made using 300 mA, 0.1 second and 75 kV exhibits motion unsharpness but otherwise satisfactory technical quality. The image will be repeated using a shorter exposure time. Using 86 kV and 400 mA, what should be the new exposure time?

Back 191

37 ms

Front 192

The radiograph shown in Figure 4-23 was made using screen/film technique and exhibits an artifact caused by

Back 192

Static electricity

Front 193

X-ray tubes used in CT differ from those used in x-ray, in that CT x-ray tubes must

Back 193

1. Have very high-short exposure rating

2. Capable of tolerating several million heat units

3. Have small focal spot for optimal resolution

Front 194

Figure 4-24 is representative of

Back 194

The inverse square law

Front 195

Which of the following can impact the visibility of the anode heel effect?

Back 195

1. SID

2. IR size

Front 196

When involuntary motion must be considered in SF imaging, the exposure time may be cut in half if the kilovoltage is

Back 196

Increased by 15%

Front 197

Which of the following groups of exposure factors would be most effective in eliminating prominent pulmonary vascular markings in the RAO position for a sternum?

Back 197

25 mA, 7/10 second, 70 kV

Front 198

An exposure was made of part using 300 mA and 0.06 second with a 200-speed screen-film combination. An additional radiograph is requested using a 400-speed system to reduce motion unsharpness. Using 400 mA, all other factors remaining constant, what should be the new exposure time?

Back 198

22ms

Front 199

The image seen in Figure 4-25 was made using screen-film technique and the film was processed in a chemical film processor. The artifacts seen on the resulting radiograph are called

Back 199

Guide-shoe marks

Front 200

HVL is affected by the amount of

Back 200

1. kVp

2. Beam filtration

Front 201

The attenuation of x-ray photons is not influenced by

Back 201

3. Photon quantity

Front 202

If, upon QC testing, the HVL of the X-ray beam produced by a particular x-ray tube increases, it is an indication of

Back 202

1. Vaporized tungsten deposited on the inner surface of the glass envelope

2. An increase in the kilovoltage being produced by the tube

Front 203

A compensating filter is used to

Back 203

Even out widely differing tissue densities

Front 204

Boxes of film stored in too warm an area may be subject to

Back 204

Film fog

Front 205

Which of the following will influence spatial resolution?

Back 205

2. Part motion

3. Focal spot

Front 206

Which interaction is responsible for producing the most x-ray photons at the x-ray tube target?

Back 206

Brems

Front 207

Factors that determine the production of scattered radiation include

Back 207

1. Field size

2. Beam restriction

3. Kilovoltage

Front 208

Which of the following are classified as rare earth phosphors?

Back 208

1. Lanthanum oxybromide

2. Gadolinium oxysulfide

Front 209

Which of the following is the most appropriated critique for the image seen as Figure 4-26?

Back 209

Low ratio/no grid used

Front 210

As grid ratio is decreased in analog/SF imaging,

Back 210

The scale of contrast becomes longer

Front 211

X-ray film emulsion is most sensitive to safelight fog

Back 211

After exposure

Front 212

Which of the following focal-spot sizes should be employed for magnification radiography?

Back 212

0.2 mm

Front 213

If a 6'' OID is introduced during a particular radiographic exam, what change in SID will be necessary to overcome objectionable magnification?

Back 213

The SID must be increased by 42''

Front 214

If a particular grid has lead strips 0.40 mm thick, 4.0 mm high, and 0.25 mm apart, what is its grid ratio?

Back 214

16:1

Front 215

The line-focus principle expresses the relationship between

Back 215

The actual and the effective focal spot

Front 216

Which of the following has the greatest effect on radiographic IR exposure?

Back 216

SID

Front 217

Shape distortion is influenced by the relationship between the

Back 217

1. X-ray tube and the part being imaged

2. Part to be imaged and the IR

3. IR and the x-ray tube

Front 218

The flattened hemidiaphragms and widened intercostal spaces seen in Figure 4-27 are representative of

Back 218

Emphysema

Front 219

IR's frequently have a rear lead-foil layer that functions to

Back 219

Absorb backscatter

Front 220

The continued emission of light by a phosphor after the activating source has ceased is termed

Back 220

Phosphorescence

Front 221

Which combination of exposure factors most likely will contribute to producing the shortest-scale contrast?

Back 221

20 80 400 10:1 8 x 10 inch

Front 222

How often are radiographic equipment collimators required to be evaluated?

Back 222

Semiannually

Front 223

During CR imaging, the latent image present on the PSP is changed a computerized image by the

Back 223

ADC

Front 224

Exposed silver halide crystals are changed to black metallic silver by the

Back 224

Reducers

Front 225

Grid cutoff due to off-centering would result in

Back 225

Overall loss of receptor exposure

Front 226

The advantages of high kilovoltage chest radiography is that

Back 226

1. Exposure latitude is increased

2. It produces long-scale contrast

3. It reduces patient dose

Front 227

The exposure factors of 400 mA, 70 ms, and 78 kV were used to produce a particular image receptor exposure. A similar image could be produced using 500 mA, 90 kV, and

Back 227

28 ms

Front 228

Pathologic or abnormal conditions that would require a decrease in exposure factors include all of the following except

Back 228

Pneumonia

Front 229

The artifacts seen in Figure 4-28 include

Back 229

2. Jewelry artifacts

3. Hair braid artifacts

Front 230

Geometric unsharpness is directly influenced by

Back 230

1. OID

Front 231

Which of the following are associated with magnification fluoroscopy?

Back 231

1. Less noise

2. Improved contrast resolution

3. Improved spatial resolution

Front 232

Which of the following may be used to reduce the effect of scattered radiation on the radiographic image?

Back 232

1. Grids

2. Collimators

3. Compression bands

Front 233

Which of the following is directly related to photon energy?

Back 233

1. Kilovoltage

Front 234

What info, located on each box of film, is important to note and has a direct relationship to image quality?

Back 234

Expiration date

Front 235

If 40 mAs and a 200-speed screen-film system were used for a particular exposure, what new milliampere-seconds value would be required to produce the same density if the screen-film system were changed to a 800 speed?

Back 235

10

Front 236

An exposure was made using 8 mAs and 60 kV. If the kilovoltage was changed to 70, what new milliampere-seconds value is required to maintain receptor exposure?

Back 236

4

Front 237

Methods that help to reduce the production of scattered radiation include using

Back 237

1. Compression

2. Beam restriction

Front 238

Compression of the breast during mammography imaging improves the technical quality of the image because

Back 238

1. Geometric blurring is decreased

2. Less scattered radiation is produced

3. Patient motion is reduced

Front 239

Distortion can be caused by

Back 239

1. Tube angle

2. The position of the organ or structure within the body

3. The radiographic positioning of the part

Front 240

Which of the following possessed he widest dynamic range?

Back 240

CR

Front 241

Which of the following statements are true with respect to the radiographic shown in Figure 4-29?

Back 241

1. The image exhibits long-scale contrast

2. The image exhibits a clothing artifact

3. The image demonstrates motion blur

Front 242

What is the relationship between tissue attenuation coefficient in CT and its related Hounsfield unit (HU)?

Back 242

The greater the tissue attenuation coefficient, the higher the HU value

Front 243

A grid usually is employed in which of the following circumstances?

Back 243

1. The radiographing a large or dense body part

2. When using high kilovoltage

Front 244

Exposure factors of 90 kV and 3 mAs are used for a particular non grid exposure. What should be the new milliampere-seconds (mAs) value if a 12:1 grid is added?

Back 244

15

Front 245

An exposure was made using 300 mA, 40 ms exposure, and 85 kV. Each of the following changes will decreases the receptor exposure by one half except a change to

Back 245

10 mAs

Front 246

Which of the following are true when comparing screen-film imaging to CR imaging?

Back 246

1. CR DQE is better than screen-film DQE

2. CR has a wider exposure range than screen-film

Front 247

Which of the following are methods used for x-ray film silver reclamation?

Back 247

2. Metallic replacement method

3. Electrolytic method

Front 248

Which of the following groups of technical factors would be most appropriate for the radiographic exam should in Figure 4-30?

Back 248

400 mA, 1/30 second, 72 kV

Front 249

In which of the following exams should 70 kV not be exceeded?

Back 249

Intravenous urogram (IVU)

Front 250

Which of the following statements are true regarding the artifact seen in the erect PA projection of the chest seen in Figure 4-31?

Back 250

The object is located within the IP