RAD 361 Exam and Quiz Ch 10-11

When radiographic technical factors are adjusted to provide an acceptable image and then filtration is added to the x-ray tube, which of the following will increase? Select one: a. Optical density b. Patient dose c. Radiographic contrast d. Average energy of the x-ray beam e. Spatial resolution

d. average energy of the x-ray beam

Approximately _______% of the x-ray beam incident on the patient is transmitted through the patient without interaction to become part of the image-forming beam. Select one: a. 90-99 b. 80-89 c. 20-29 d. 1

d. 1

Distortion can be caused by: 1. tube angle 2. the position of the organ or structure within the body 3. the radiographic positioning of the part Select one: a. 1 only b. 1 and 2 only c. 2 and 3 only d. 1, 2, and 3

d. 1, 2, and 3

If the SID is 100cm and an object is placed 20 cm from the image receptor, what is the magnification factor (MF)? a. 5 b. 0.8 c. 0.2 d. 1.25 e. 10

d. 1.25

Which of the following technique factors should result in the highest patient dose? Select one: a. 100 mA, 500 ms, 60 kVp, no grid b. 200 mA, 750 ms, 50 kVp, 16:1 grid c. 400 mA, 100 ms, 60 kVp, no grid d. 600 mA, 700 ms, 70 kVp, 8:1 grid e. 800 mA, 200 ms, 80 kVp, 8:1 grid

d. 600 mA, 700 ms, 70 kVp, 8:1 grid

Assume that the usual exposure time for a lateral cervical spine radiograph at 100 cm SID is 100 ms. At an SID of 90 cm, all other factors remaining the same, the correct exposure time would be: (Hint: you do know how to do this, think about the "direct square law or mAs density maintenance formula) Select one: a. 10 ms b. 25 ms c. 50 ms d. 80 ms e. 180 ms

d. 80 ms

Contrast resolution is improved by _____________. Select one: a. tight collimation b. lowering kVp c. patient compression d. All of the above

d. all of the above

Patient thickness affects image quality by affecting ____________. Select one: a. magnification b. radiographic contrast c. focal spot blur d. All of the above

d. all of the above

Spatial resolution improves with decreased _________ blur. Select one: a. screen b. motion c. geometric d. All of the above

d. all of the above

The use of __________ improves contrast and reduces patient dose. Select one: a. collimation b. high kVp c. low kVp d. less filtration

a. collimation

The chest represents high-contrast anatomy (high subject contrast). Therefore, which of the following is most appropriate? Select one: a. High kVp b. High mAs c. Long SID d. Low kVp e. Low mAs Feedback

a. high kVp

As field size is increased, scatter radiation: Select one: a. Increases b. Is reduced c. Is removed d. Is reversed e. Remains constant

a. increases

All the following are related to spatial resolution, except: Select one: a. milliamperage b. focal spot size c. SID d. OID

a. milliamperage

Decreasing the kVp will increase ___________. Select one: a. patient dose b. image noise c. Compton scatter d. optical density

a. patient dose

To minimize magnification, one should do which of the following? Select one: a. Position the object as close to the IR as is practical b. Position the x-ray tube as close to the patient as is practical c. Use high kVp, low mAs d. Use the large focal spot e. Use the small focal spot

a. position the object as close to the IR as is practical

Radiographic image quality is improved when the __________ is increased. Select one: a. source image distance b. focal spot size c. film speed d. screen speed

a. source image distance

A high quality radiograph should always demonstrate ____________. Select one: a. structures and tissues b. high contrast c. minimum magnification d. All of the above

a. structures and tissues

The x-rays that are transmitted through the patient without interaction contribute to ______________. Select one: a. useful information b. film fog c. image noise d. All of the above

a. useful information

An image receptor with ____________ can be used over a greater range of exposures. Select one: a. wide latitude b. high contrast c. narrow latitude d. high average gradient

a. wide latitude

What is the formula for the magnification factor? Select one: a. MF = SID/SOD b. MF = SOD/SID c. MF = (SID/SOD)2 d. MF = SID2/SOD

a. MF = SID/SOD

To reduce magnification, one should do which of the following? a. Reduce OID b. Reduce SID c. Reduce SSD d. Use the small focal spot e. Use tighter collimation

a. Reduce OID

Which of the following would principally reduce the production of scatter radiation? Select one: a. A decrease in field size b. A decrease in SID c. An increase in SSD d. Use of a filter e. Use of a grid

a. a decrease in field size

Focal spot blur can be reduced by using __________. Select one: a. a small focal spot b. a shorter SID c. a larger OID d. All of the above

a. a small focal spot

Distortion primarily occurs: Select one: a. Because subject anatomy is inclined b. Because subject anatomy is thick rather than thin c. When improper kVp was selected d. When subject anatomy is flat e. When subject anatomy lies parallel to the image receptor

a. because subject anatomy is inclined

Distortion: Select one: a. Can be corrected by proper patient positioning b. Is controlled by focal-spot size c. Never accompanies magnification d. Occurs only lateral to the central axis of the x-ray beam e. Occurs only when the image is inclined

a. can be corrected by proper patient positioning

Causes of grid cutoff, when using a focused reciprocating grid include the following? 1. Inadequate SID 2. X-ray tube off-center with the long axis of the lead strips 3. Angling the beam in the direction of the lead strips Select one: a. 1 only b. 1 and 2 only c. 2 and 3 only d. 1, 2, and 3

a. 1 only

Which kVp selection would result in the most scattered x-rays in the image-forming beam? Select one: a. 90 kVp b. 75 kVp c. 60 kVp d. 50 kVp

a. 90 kVp

In a radiographic examination of the lumbar spine, which of the following techniques would result in greatest exposure to the patient? Select one: a. 80 kVp/100 mAs b. 70 kVp/200 mAs c. 95 kVp/50 mAs d. 110 kVp/25 mAs e. 120 kVp/25 mAs

b. 70 kvp/200 mAs

Which of the following conditions contributes least to image distortion? Select one: a. Thick object at a short SID b. A thin object at a long SID c. Angling the CR d. Object position e. Off-axis imaging

b. a thin object at a long SID

Scatter radiation reduces radiographic quality by changing: Select one: a. Blurring b. Contrast c. Distortion d. Mass Density e. Optical density

b. contrast

Use of contrast media principally affects which of the following? Select one: a. Blur b. Contrast resolution c. Mass density d. Optical density e. Speed

b. contrast resolution

Reducing field size through proper collimation usually results in improved (select all that apply): Select one or more: a. Blur b. Contrast resolution c. Magnification d. Patient dose e. Spatial resolution

b. contrast resolution d. patient dose

Scatter radiation increases as ___________________ increases. Select one: a. photoelectric absorption b. field size c. filtration d. contrast

b. field size

Which of the following factors that affect scatter radiation can be controlled by the radiologic technologist? a. Added filtration b. Field size c. Inherent filtration d. mAs e. patient thickness

b. field size

Which of the following is most responsible for radiographic spatial resolution? Select one: a. Film graininess b. Focal-spot size c. Screen mottle d. SID e. Use of a grid

b. focal spot size

When radiographic technique factors are adjusted to obtain an acceptable image, patient dose will increase as which of the following increases? Select one: a. IR speed b. Grid ratio c. SID d. SOD e. SSD

b. grid ratio

Compton scatter contributes to _____________. Select one: a. useful information b. image noise c. image contrast d. All of the above

b. image noise

An UGI image demonstrates motion blur. To increase image detail, the radiologic technologist could do which of the following? Select one: a. Increase grid ratio b. Increase kVp and reduce exposure time c. Increase mA and exposure time d. Reduce OID e. Reduce SID

b. increase kVp and reduce exposure time

Higher speed image receptors generally produce images with ____________. Select one: a. better resolution b. increased noise c. higher contrast d. improved detail

b. increased noise

Which of the following does not affect image blur? Select one: a. Focal-spot size b. kVp c. OID d. SID e. SOD

b. kVp

When kVp is increased with a compensating reduction in mAs, which of the following is reduced? Select one: a. Optical density b. Patient dose c. Remnant radiation d. Scatter proportion e. Spatial resolution

b. patient dose

Distortion can be reduced by ____________________________. Select one: a. placing the object plane perpendicular to the image plane b. placing the object plane parallel to the image plane c. directing the central ray 15° from the object plane d. increasing the SID and the OID

b. placing the object plane parallel to the imaging plane

Focal-spot blur can be reduced by: Select one: a. Increasing focal-spot size b. Reducing OID c. Reducing SID d. Reducing SSD

b. reducing OID

_________ is defined as the ability to image two separate objects and visually detect one from the other. Select one: a. Contrast b. Resolution c. Detail d. Noise

b. resolution

Focal spot blur is greatest Select one: a. directly along the course of the central ray b. toward the cathode end of the x-ray beam c. toward the anode end of the x-ray beam d. as the SID is increased

b. toward the cathode end of the x-ray beam

How can you improve image contrast with a heavy patient without increasing patient dose? Select one: a. Lower kVp and raise mAs. b. Use tight collimation. c. Raise kVp and lower mAs. d. Do both A and B.

b. use tight collimation

The most commonly used beam restricting device is the ____________. Select one: a. extension cone b. variable collimator c. aperture diaphragm d. compression device

b. variable collimator

A grid is used in which of the following circumstances? When radiographing a large or dense body part When using high kilovoltage When a lower patient dose is required Select one: a. 1 only b. 3 only c. 1 and 2 only d. 1, 2, 3

c. 1 and 2 only

Image magnification increases with increasing: Select one: a. Image size b. Object size c. OID d. SID e. SOD Feedback

c. OID

Which of these body parts has the highest subject contrast? Select one: a. Abdomen b. Skull c. Chest d. Pelvis

c. chest

Remnant x-rays are those that: Select one: a. Are absorbed within the patient b. Do not interact with the patient or the IR c. Exit the patient d. Interact with the patient and are scattered away e. Scatter back toward the source

c. exit the patient

Which of the following are the two general types of devices designed to control scatter radiation? Select one: a. Filtration and beam restrictors b. Filtration and image masks c. Grids and beam restrictors d. Grids and filtration e. Image masks and beam restrictors

c. grids and beam restrictors

As kVp increases, scatter radiation production will: Select one: a. decrease because of less Compton interaction b. decrease because of less photoelectric interaction c. increase because of more Compton interaction d. Increase because of more photoelectric interaction e. Remain unchanged Feedback

c. increase because of more Compton interaction

The three primary factors influencing the intensity of scatter in the image-forming beam are ___________________. Select one: a. mAs, kVp, and collimation b. mAs, filtration, and grids c. kVp, field size, and patient thickness d. filtration, patient thickness, and mAs

c. kVp, field size, and patient thickness

The three primary geometric factors affecting image quality are ________________________. Select one: a. distortion, subject contrast, and mAs b. patient thickness, distortion, and magnification c. magnification, distortion, and focal spot blur d. kVp, focal spot blur, and contrast

c. magnification, distortion, and focal spot blur

Subject contrast is affected by ___________. Select one: a. mAs b. focal spot size c. patient thickness d. voltage ripple

c. patient thickness

The x-ray interaction that contributes to the "white" areas (bone,bullet) of the image is _____________. Select one: a. coherent scatter b. Compton interaction c. photoelectric interaction d. pair production

c. photoelectric interaction

Image magnification can be reduced with the use of which of the following? Select one: a. A cone b. Increased filtration c. Shorter OID d. Shorter SID e. Shorter SSD Feedback

c. shorter OID

Magnification is reduced by which of the following? Select one: a. Increasing kVp b. Increasing speed of the system c. Increasing SID and OID d. Increasing SID and reducing OID e. Reducing focal-spot size

d. increasing SID and reducing OID

In general, a mammogram should be taken with: Select one: a. A generalization about this is not possible; decisions are dependent on thickness b. High kVp and high mAs c. High kVp and low mAs d. Low kVp and high mAs e. Low kVp and low mAs

d. low kVp and high mAs

Absorption blur is most closely related to which of the following? Select one: a. Film blur b. Focal-spot blur c. Geometric blur d. Object shape

d. object shape

Another term for focal-spot blur is: Select one: a. Actual focal spot b. Disumbra c. Effective focal spot d. Penumbra e. Umbra

d. penumbra

Sharpness of detail on a radiograph is principally improved by which of the following? Select one: a. Increasing kVp b. Increasing scatter radiation c. Reducing image noise d. Reducing patient motion e. Reducing radiation dose Feedback

d. reducing patient motion

As kVp is increased from 70 to 80, which of the following has the highest likelihood of happening? Select one: a. Contrast resolution will improve b. The mAs must be increased c. The SID must be increased d. There will be a higher proportion of scatter radiation e. There will be a lower proportion of scatter radiation

d. there will be a higher proportion of scatter radiation

A radiograph that exhibits a long grayscale contrast has which of the following features? a. Few shades of gray that have great differences b. Few shades of gray that have minimal differences c. Good spatial resolution d. Many shades of gray that have great differences e. Many shades of gray that have minimal differences

e. Many shades of gray that have minimal differences

Increasing which of the following is effective in reducing focal-spot blur? Select one: a. Focal-spot size b. kVp c. Object size d. OID e. SID

e. SID

Subject contrast is enhanced with the use of contrast media because: Select one: a. Absorption blur is reduced b. Compton effect is increased c. Focal-spot blur is reduced d. Mass density is increased e. Photoelectric interaction is increased

e. photoelectric interaction is increased

Short exposure times are recommended for radiography of the stomach to do which of the following? Select one: a. Enhance contrast b. Improve spatial resolution c. Minimize geometric blur d. Reduce magnification e. Reduce motion blur

e. reduce motion blur

A foreshortened image: Select one: a. Can be corrected by increasing kVp and reducing mAs b. Can be corrected by reducing kVp and increasing mAs c. Can be corrected by reducing SID d. Can never be smaller than the object e. Results from an inclined object

e. results from an inclined object

Typical "well-done" extremity radiographs result in which of the following? Select one: a. High distortion b. High noise c. High patient dose d. Long-scale contrast e. Short-scale contrast

e. short-scale contrast

Radiographic spatial resolution is improved by the use of which of the following? Select one: a. A grid b. A larger focal spot c. Reduced kVp d. Reduced mAs e. Slower speed imaging systems

e. slower speed imaging systems

The sharpness of detail in a radiograph is best increased by the use of which of the following? Select one: a. High-speed IR's b. Large focal spot c. Long SID d. Medium-speed IR's e. Small focal spot

e. small focal spot

Focal-spot blur can be reduced by which of the following? Select one: a. Increasing kVp b. Increasing mAs c. Increasing OID d. Reducing SOD e. Using the small focal spot

e. using the small focal spot