Deck 11: Radiographic Exposure Technique

Question 1

Which of the following is not a primary exposure technique factor?

A) KVP
B) Time of exposure
C) SID
D) MA

Answer 1

SID

Question 2

What type of relationship does mAs have with the quantity of x-rays produced?

A) Direct proportional
B) Direct but not proportional
C) Inverse proportional
D) Inverse but not proportional

Answer 2

Direct proportional

Question 3

Using 20 mAs on a knee image (digital IR) when only 8 mAs was needed to produce sufficient remnant radiation results in

A) a dark image
B) an image with appropriate brightness
C) unnecessary patient radiation dose
D) an image with appropriate brightness and unnecessary patient radiation dose

Answer 3

an image with appropriate brightness and unnecessary patient radiation dose

Question 4

In digital imaging, the reason(s) mAs does not affect brightness is/are:

A) wide dynamic range
B) matrix size
C) computer processing
D) wide dynamic range and computer processing only

Question 5

Which of the following is true regarding the effect of mAs on the brightness of a digital image.

A) doubling the mAs will increase brightness
B) halfing the mAs will decrease brightness
C) mAs does not affect brightness in a digital image
D) doubling the mAs will increase brightness and halfing the mAs will decrease brightness

Question 6

If the mA is 600 and exposure time is 10 ms, how can the mAs be doubled?

A) Increase the mA to 1200.
B) Increase the time to 20 ms.
C) Increase the mAs to 12 mAs.
D) Any of the above is correct.

Question 7

With digital imaging, the relationship between mAs and image brightness is

A) direct
B) direct proportional
C) inverse
D) none of these

Question 8

How much mAs is produced when the mA is 800 and the exposure time is 30 ms?

A) 24 mAs.
B) 240 mAs.
C) 2,400 mAs.
D) 24,000 mAs

Question 9

How much mAs is produced when the mA is 50 and the exposure time is 4000 ms?

A) 20 mAs.
B) 200 mAs.
C) 2,000 mAs.
D) 20,000 mAs.

Question 10

With digital imaging, if the mAs is too high

A) the image brightness will appear low (dark)
B) the image brightness will appear appropriate
C) the image brightness will appear high (light)
D) none of these

Question 11

With digital imaging, overexposure of the IR and excessive dose to the patient can be

A) easily determined by looking at the image brightness
B) difficult to determine by looking at the image brightness
C) determined by checking the exposure indicator value
D) difficult to determine by looking at the image brightness and determined by checking the exposure indicator value

Question 12

How much mAs is produced when the mA is 200 and the exposure time is 0.5 s?

A) 25 mAs.
B) 50 mAs.
C) 100 mAs.
D) 200 mAs.

Question 13

What mA should be selected to produce 32 mAs using a 0.04 exposure time?

A) 128 mA.
B) 200 mA.
C) 400 mA.
D) 800 mA.

Question 14

If a radiographic image has to be repeated because of an exposure error, the mAs must be changed by a factor of at least

A) 1
B) 2
C) 4
D) 30

Question 15

Which of the following has an effect on how much mAs is used for a specific examination?

A) generator type.
B) pathologic conditions present.
C) a patient's age.
D) All of these.

Question 16

Given 40 mAs, doubling the mA produces the same result as

A) doubling the time of exposure
B) doubling the mAs
C) halving the mAs
D) doubling the time of exposure and doubling the mAs
E) doubling the time of exposure and halving the mAs

Question 17

With digital imaging, if the image receptor is not exposed to enough radiation,
1) The image brightness will appear appropriate.
2) The image brightness will appear high (light).
3) Quantum noise will be visible

A) The image brightness will appear appropriate and the image brightness will appear high (light) only
B) The image brightness will appear appropriate and quantum noise will be visible only
C) The image brightness will appear high (light) and quantum noise will be visible only
D) The image brightness will appear appropriate, the image brightness will appear high (light), and quantum noise will be visible

Question 18

With digital imaging, if the image receptor is not exposed to enough radiation

A) the image brightness will appear low (dark)
B) the image brightness will appear appropriate
C) the image brightness will appear high (light)
D) none of these

Question 19

Which of the following exposure factors produces 25 mAs?

A) 250 mA @ 1 s.
B) 125 mA @ 2 s.
C) 200 mA @ 0.2 s.
D) 250 mA @ 100 ms.

Question 20

In maintaining the same mAs, there is a(n) ________________ relationship between mA and exposure time.

A) direct
B) inverse
C) double
D) half

Question 21

The relationship between kVp and the quantity of remnant radiation is known as the

A) kVp-brightness rule
B) 15% rule
C) 25% rule
D) kVp-quantity rule

Question 22

Increasing the kVp

A) increases the energy of the x-ray photons
B) increases the quantity of x-ray photons
C) increases the penetrating power of x-ray photons
D) all of these

Question 23

Standard radiographic x-ray tubes have large focal spots that measure approximately

A) 0.5-0.6 mm
B) 0.6-1 mm
C) 1-1.2 mm
D) 0.5-1.2 mm

Question 24

Which of the following exposure factors produces the same amount of remnant radiation as does 20 mAs at 70 kVp?

A) 10 mAs @ 70 kVp.
B) 10 mAs @ 81 kVp.
C) 40 mAs @ 60 kVp.
D) 10 mAs @ 81 kVp and 40 mAs @ 60 kVp.

Question 25

What type of relationship does kVp have with exposure to the image receptor (IR)?

A) direct
B) inverse
C) inverse proportional
D) no relationship

Question 26

When the intensities of radiation exiting the patient are very similar, the resulting radiographic image has

A) low contrast
B) high contrast
C) short-scale contrast
D) low contrast and short-scale contrast

Question 27

Low kVp results in the intensities of radiation exiting the patient being ____________.

A) similar
B) different
C) homogenous
D) none of these

Question 28

When the intensities of radiation exiting the patient are very different from each other, the resulting radiographic image has

A) low contrast
B) high contrast
C) short-scale contrast
D) high contrast and short-scale contrast

Question 29

What is the relationship between kVp and subject contrast?

A) high kVp creates low subject contrast
B) low kVp creates low subject contrast
C) high kVp creates high subject contrast
D) kVp does not affect subject contrast

Question 30

Kilovoltage is not usually used to adjust exposure to the image receptor because

A) it has too great an effect on patient exposure
B) it is too difficult to determine how much it should be changed
C) it affects contrast
D) it affects spatial resolution

Question 31

Standard radiographic x-ray tubes have small focal spots that measure approximately

A) 0.5-0.6 mm
B) 0.6-1 mm
C) 1-1.2 mm
D) 0.5-1.2 mm

Question 32

Focal spot size is determined by

A) the amount of kVp
B) cathode filament size
C) cathode focusing cup size
D) the exposure time

Question 33

Too little remnant radiation caused by low kVp results in a digital image in which

A) the image brightness appears high (light)
B) the image brightness appears appropriate
C) quantum noise is visible
D) the image brightness appears appropriate and quantum noise is visible

Question 34

To maintain the same amount of radiation reaching the IR, if the kVp is increased by 15% the mAs needs to

A) remain the same
B) be doubled
C) be halved
D) be decreased by a minimum of 30%

Question 35

Increasing the kVp has what affect on wavelength and frequency?

A) decreases wavelength and decreases frequency
B) increases wavelength and decreases frequency
C) increases wavelength and increases frequency
D) decreases wavelength and increases frequency

Question 36

Increasing the kVp by 15% has the same effect as

A) increasing the mAs by 15%
B) doubling the mAs
C) decreasing the mAs by 15%
D) halving the mAs

Question 37

Using excessive kVp with a digital IR results in
1) increased IR exposure
2) increased scatter reaching the IR
3) decreased contrast

A) increased IR exposure and increased scatter reaching the IR only
B) increased IR exposure and decreased contrast only
C) increased scatter reaching the IR and decreased contrast only
D) increased IR exposure, increased scatter reaching the IR, and decreased contrast

Question 38

If the original exposure factors are 20 mAs @ 70 kVp, which of the following factors produce a radiographic image with the same IR exposure but higher contrast?

A) 10 mAs @ 81 kVp.
B) 10 mAs @ 70 kVp.
C) 40 mAs @ 70 kVp.
D) 40 mAs @ 60 kVp.

Question 39

To adjust the kVp to produce the desired contrast level, the kVp must first be

A) as low as possible for radiation safety
B) as high as possible
C) high enough to penetrate the part
D) high enough to reduce noise

Question 40

With digital imaging, if the kVp is too high

A) the image brightness appears low (dark)
B) the image brightness appears appropriate
C) the image brightness appears high (light)
D) none of these

Question 41

When the distance is increased from 20 inches to 40 inches, the beam intensity

A) increases* 2
B) decreases by
C) stay the same
D) decreased by

Question 42

The distance between the x-ray focal spot and the image receptor is the

A) OID
B) SID
C) MF
D) SOD

Question 43

Doubling the mAs produces appropriate exposure to the IR when the SID is changed from 40 inches to

A) 36 inches SID
B) 48 inches SID
C) 56 inches SID
D) 60 inches SID

Question 44

The distance between the object being imaged and the image receptor is the

A) OID
B) SID
C) MF
D) SOD

Question 45

Changes in SID affect
1) spatial resolution
2) beam intensity
3) magnification

A) spatial resolution and beam intensity only
B) spatial resolution and magnification only
C) beam intensity and magnification only
D) spatial resolution, beam intensity, and magnification

Question 46

To maintain the same exposure to the IR, if the SID is increased, the mAs must be

A) decreased
B) increased
C) left the same
D) doubled

Question 47

Which of the following is the correct formula for the direct square law formula?

A) mAs1/mAs2 = SID1/SID2.
B) mAs1/mAs2 = SID2/SID1.
C) mAs1/mAs2 = (SID1)2/(SID2)2.
D) mAs1/mAs2 = (SID2)2/(SID1)2.

Question 48

If the intensity of radiation at 36 inches SID is 600 mR, what is the intensity if the distance is increased to 60 inches SID?

A) 216 mR.
B) 359.9 mR.
C) 1000 mR.
D) 1666.7 mR.

Question 49

_________ SID is typically used to image the chest so that the heart is seen with minimal magnification.

A) 30 inches
B) 40 inches
C) 72 inches
D) 90 inches

Question 50

If 12 mAs produce appropriate IR exposure at 36 inches SID, how much mAs is needed at 72 inches SID to maintain that amount of exposure to the IR?

A) 3 mAs.
B) 6 mAs.
C) 24 mAs.
D) 48 mAs.

Question 51

If the intensity of radiation at 36 inches is 480 mR, what is the intensity if the SID is increased to 72 inches?

A) 360 mR.
B) 240 mR.
C) 120 mR.
D) 60 mR.

Question 52

What type of relationship does distance have with x-ray beam intensity?

A) Direct proportional.
B) Direct but not proportional.
C) Inverse proportional.
D) Inverse but not proportional.

Question 53

When the SID is decreased from 72 inches SID to 40 inches SID, how is the radiation reaching the IR affected and does mAs need to be adjusted?

A) increases radiation to IR; decrease mAs
B) decreases radiation to IR; increase mAs
C) increases radiation to IR; increase mAs
D) decreases radiation to IR; decrease mAs

Question 54

If 10 mAs produce appropriate IR exposure at 40 inches SID, how much mAs is needed at 48 inches SID to maintain that amount of IR exposure?

A) 7 mAs.
B) 8 mAs.
C) 12 mAs.
D) 14 mAs.

Question 55

When a known mAs at 72 inches SID produces appropriate exposure to the IR, one half of the mAs can be used at

A) 40 inches SID
B) 48 inches SID
C) 56 inches SID
D) 60 inches SID

Question 56

Using a higher SID

A) increases magnification
B) decreases magnification
C) increases size distortion
D) none of these

Question 57

Which of the following is the correct formula for the inverse square law?

A) I1/I2 = D1/D2.
B) I1/I2 = D2/D1.
C) I1/I2 = (D1)2/(D2)2.
D) I1/I2 = (D2)2/(D1)2.

Question 58

If the intensity of radiation at 72 inches is 225 mR, what is the intensity if the SID is decreased to 40 inches?

A) 69.4 mR.
B) 125 mR.
C) 405 mR.
D) 729 mR.

Question 59

If 16 mAs produce appropriate IR exposure at 72 inches SID, how much mAs is needed at 48 inches SID to maintain that amount of IR exposure?

A) 7 mAs.
B) 11 mAs.
C) 24 mAs.
D) 36 mAs.

Question 60

Focal spot size affects only

A) brightness
B) contrast
C) sharpness
D) noise

Question 61

Which of the following is the formula to determine magnification factor?

A) MF = SID/OID.
B) MF = SID/SOD.
C) MF = SOD/SID.
D) MF = OID/SID.

Question 62

The indication of how much magnification is seen on a radiograph is

A) OID
B) SID
C) MF
D) SOD

Question 63

The device used to absorb scatter radiation in the radiation leaving the patient before it reaches the image receptor is the

A) cassette
B) flat panel detector
C) grid
D) filter

Question 64

The formula that can be used to calculate the object size when the image size and MF are known is

A) object size = MF/image size
B) object size = image size/MF
C) object size = image size * MF
D) none of these

Question 65

If a 12:1 ratio grid is used in a procedure that previously used no grid and 4 mAs, how much mAs should be used with the grid?

A) 0.33 mAs.
B) 1.25 mAs.
C) 20 mAs.
D) 48 mAs.

Question 66

The distance between the x-ray focal spot and the object being imaged is the

A) OID
B) SID
C) MF
D) SOD

Question 67

Which of the following is the correct formula to determine how mAs should be adjusted when different ratio grids are used?

A) mAs1/mAs2 = grid conversion factor2/grid conversion factor1.
B) mAs1/mAs2 = grid conversion factor1/grid conversion factor2.
C) mAs1/mAs2 = (grid conversion factor2)2/(grid conversion factor1)2.
D) mAs1/mAs2 = (grid conversion factor1)2/(grid conversion factor2)2.

Question 68

If 40 mAs produce a diagnostic image when a 12:1 ratio grid is used, how much mAs should be used with a 5:1 ratio grid?

A) 6.7 mAs.
B) 16 mAs.
C) 96 mAs.
D) 100 mAs.

Question 69

Whenever magnification is increased

A) spatial resolution is decreased
B) spatial resolution is increased
C) spatial resolution stays the same
D) exposure to the image receptor increases

Question 70

What is the size of the object when the MF is 1.3 and the image size is 3 cm?

A) 0.43 cm.
B) 1.3 cm.
C) 2.3 cm.
D) 3.9 cm.

Question 71

Deciding to use a grid for a radiographic examination requires use of

A) increased SID
B) decreased SID
C) increased mAs
D) decreased mAs

Question 72

If 25 mAs produce a diagnostic image when a 6:1 ratio grid is used, how much mAs should be used with a 12:1 ratio grid?

A) 13 mAs.
B) 15 mAs.
C) 42 mAs.
D) 50 mAs.

Question 73

Which of the following results in the greatest amount of magnification.
1) increased SID
2) decreased SID
3) increased OID

A) increased SID and increased OID only
B) decreased SID and increased OID only

Question 74

Reducing the amount of scatter radiation reaching the IR results in

A) lower radiographic contrast
B) higher radiographic contrast
C) improved spatial resolution
D) reduced spatial resolution

Question 75

If the magnification factor is 1.25, the image is ______________ than the object.

A) 25% smaller
B) 125% smaller
C) 25% larger
D) 125% larger

Question 76

When a patient cannot fully extend his or her leg for a knee image, resulting in the knee being 4 inches away from the image receptor, what is the MF if the SID is 40 inches?

A) 0.1.
B) 0.9.
C) 1.11.
D) 10.

Question 77

When OID cannot be reduced, it is possible to reduce size distortion by

A) increasing mAs
B) increasing SID
C) using a small focal spot size
D) decreasing SID

Question 78

Increased collimation results in
1) less volume of tissue irradiated
2) less exit radiation reaching the IR
3) less scatter reaching the IR

A) less volume of tissue irradiated and less exit radiation reaching the IR only
B) less volume of tissue irradiated and less scatter reaching the IR only
C) less exit radiation reaching the IR and less scatter reaching the IR only
D) less volume of tissue irradiated, less exit radiation reaching the IR, and less scatter reaching the IR

Question 79

The formula to determine the SOD (source to object distance) is

A) SOD = SID - OID
B) SOD = OID - SID
C) SOD = SID + OID
D) none of these

Question 80

The only factor that affects exposure to the image receptor, size distortion, and image contrast is

A) SID
B) mAs
C) focal spot size
D) OID