V1 - Safety

Question 1

A Bremsstrahlung interaction is best described by which statement?

Answer 1

An electron is slowed and changes direction

Question 2

When the frequency of the voltage waveform supplied to the x-ray tube is increased, what aspect is reduced? (3 answers)

Answer 2

• Patient exposure.
• Heat loading on the anode disk.
• Average wavelength of the x-ray beam.

Question 3

Which feature of the fluoroscopic equipment is designed to reduce entrance skin exposure to the patient?

Answer 3

Beam Filtration

Question 4

What is the dose-response relationship of radiation-induced skin cancer?

Answer 4

Threshold

Question 5

Which term refers to the radiation that exits the x-ray tube through the collimator?

Answer 5

Primary

Question 6

A portable knee exam performed in the operating room results in beam intensity of 2.5 mgy at 32 inches. What is the intensity of the beam if the same exposure factors are used for a post-op knee at a distance of 40 inches?

Answer 6

1.60 mgy

Question 7

For which long term effect is a 28-year-old radiographer with a cumulative effective dose (CumEfD) of 200 mSv (20 rem) at an increased risk?

Answer 7

Cancer

Question 8

What is the term for a reduction in x-ray photon intensity as it passes through the patient?

Answer 8

Attenuation

Question 9

If a radiographer recieves an exposure of 0.05 msv at a distance of 1.5 feet from the tube of a portable x-ray unit, what will the exposure be at a distance of 6 feet from the tube?

Answer 9

0.003 msv

Question 10

What is the impact of using 2.5 mm of al/eq filtration on the primary x-ray beam?

Answer 10

Reduction of the patient’s skin dose

Question 11

The Z number of oxygen is 8. The elemental oxygen atom has two electron shells. How many electrons occupy an electrically neutral oxygen atom’s outer shell?

Answer 11

6

Question 12

Which protective feature is designed to reduce exposure to the patient during fluoroscopic procedures?

Answer 12

Foot switch

Question 13

As a result of imaging pregnant patient’s, which is the fetal exposure for most radiographic exams?

Answer 13

Less than 0.01 gray (1 rad)

Question 14

Which accurately describes the radiation dose absorbed by bone marrow?

Answer 14

The dose will be less than the entrance skin exposure

Question 15

In an x-ray tube, what is the source of electrons used to make x-rays?

Answer 15

Filament

Question 16

Which process describes the electron-target interaction in which most diagnostic x-rays are produced?

Answer 16

The filament electron misses all of the orbital electrons and interacts with the target atom nucleus

Question 17

Which input intensifier screen provides the best radiation protection to the patient during fluoroscopy?

Answer 17

25 cm

Question 18

The annual effective dose equivalent limit for infrequent exposures recommended by the National Council on Radiation Protection (NCRP) for a member of the general public is equal to how many msv?

Answer 18

5

Question 19

What causes the build-up of heat at the anode?

Answer 19

Electrons colliding with the target

Question 20

How much can exposure to the lens of the eyes be reduced by utilizing the PA projection of the cranium over the AP projection?

Answer 20

95%

Question 21

The majority of x-rays in the useful beam are created as a result of which process?

Answer 21

Fast-moving electrons approach the nucleus of the target atom and slow down.

Question 22

Which is the genetically significant dose (GSD) for the population of the United States?

Answer 22

0.20 mSv

Question 23

How can digital radiography contribute to patient dose reduction today, in spite of generally being slower in system speed than 400 speed film screen systems?

Answer 23

Higher kVp should be used in digital

Question 24

Which factor will decrease the patient’s dose during fluoroscopy?

Answer 24

Bring the image intensifier as close as possible to the patient

Question 25

Which term describes stray radiation that is emitted through the x-ray tube housing?

Answer 25

Leakage

Question 26

In a typical x-ray examination room, what is considered a secondary protective barrier?

Answer 26

Ceiling

Question 27

Which change causes a decrease in resistance and an increase in current flow?

Answer 27

Increasing the diameter of the conductor

Question 28

What characteristics do high linear energy transfer (LET) radiations have when compared with low-LET radiation?

Answer 28

Increased mass, decreased penetration

Question 29

Which statement correctly describes the LD 50/30?

Answer 29

Lethal dose for 50% of the population in 30 days

Question 30

Which aspect of electrical power is responsible for accelerating electrons in an x-ray tube?

Answer 30

Potential difference

Question 31

How can a radiographer reduce a patient's exposure during a lumbar spine series?

Answer 31

Carefully explain the procedure

Question 32

Which radiation dose is required to produce mitotic death?

Answer 32

Less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells

Question 33

The bucky slot cover should offer at least what lead thickness?

Answer 33

0.25 mm

Question 34

Which grid ratio results in the lowest dose to a patient, because less mAs is required?

Answer 34

5:1

Question 35

Where is the safest place for the radiographer to stand during fluoroscopy?

Answer 35

90 degrees and one meter from the patient

Question 36

Which statements are accurate about control monitoring badges? (2 answers)

Answer 36

- Should be kept in a distant room from the radiation area. | - Measures background exposure during transportation, handling, and storage.

Question 37

Which item can be used as an indicator of the quality of the diagnostic x-ray beam?

Answer 37

kVp

Question 38

Which items can be used as indicators of the quality of the diagnostic x-ray beam? (2 answers)

Answer 38

- HVL | - kVp

Question 39

What is the dose area product (DAP) if the collimated fields is 10 x 10 cm with a dose of 2 mgy/minute?

Answer 39

200 mgy per cm squared

Question 40

For the protection of the radiographer, how long must the exposure cord be on a mobile radiographic unit?

Answer 40

2 meters

Question 41

Which type of personnel dose monitoring devices is the best choice to monitor the whole body dosage of radiographer?

Answer 41

OSL dosimeter

Question 42

What is the minimum thickness of lead required for protective lead curtains?

Answer 42

0.25 mm lead equivalence

Question 43

What is the maximum speed of filament electrons as they travel toward the anode?

Answer 43

Half the speed of light

Question 44

What type of relationship does cell growth rate have on the sensitivity of tissues ionizing radiation?

Answer 44

Direct

Question 45

Which term best describes the process by which most x-ray-induced cellular damage occurs?

Answer 45

Indirect theory

Question 46

Which is an advantage of using a OSL dosimeter opposed to a film badge?

Answer 46

Not fogged by heat

Question 47

When dealing with radiation exposure, what is the most effective protection for the radiographer?

Answer 47

Distance

Question 48

The highest potential dose to the radiographer during c-arm fluoroscopy originates from which source?

Answer 48

The side where x-rays enter the patient

Question 49

Which condition must be met before dianostically useful characteristic x-rays can be produced?

Answer 49

An inner shell electron must be completely removed

Question 50

Which factor determines the amount of energy of a brems x-ray?

Answer 50

The distance between the filament electron and the nucleus of the target atom

Question 51

Which may be effects of fetal irradiation? (4 answers)

Answer 51

- Growth retardation. - Prenatal death. - Childhood and early adult cancers. - Spontaneous abortion.

Question 52

Which is the most appropriate reason for the application of gonadal shielding?

Answer 52

To safe guard the reproductive potential of patients

Question 53

What is the most likely consequence for a cell when an x-ray photon interacts with and inactivates the cell's master molecule?

Answer 53

Cell Death