Exposure

Question 1

the most important factor in reducing patient and operator exposure during fluoroscopy,

Answer 1

Collimation

Question 2

What is the estimated percentage of the population that are exposed to fluoroscopy yearly?

Answer 2

5%

Question 3

What happens to the patient radiation dose with magnification mode?

Answer 3

It increases
Magnification increases the patient radiation dose in proportion to the magnification mode size. The increase in exposure is calculated by the ratio the original diameter squared to the magnification mode diameter squared

Question 4

Which personnel monitoring device allows immediate reading of radiation exposure?

Answer 4

Pocket ionization chamber

Pocket ionization chambers discharge a capacitor by ionization of air within a chamber when in the presence of ionizing radiation. The rate of discharge depends on the intensity of the radiation. They are either self-reading, or are read by a special device. The self-reading versions allow immediate reading of radiation exposure by the operator.

Question 5

According to the National Council on Radiation Protection and Measurements (NCRP), how many days after the onset of menses is it safest to perform x-rays?
a) 0-5 days
b) 6-9 days
c) 10-14 days
d) Greater than 2 weeks

Answer 5

10-14 days

Question 6

All of the following have been used for somatic dose measurements EXCEPT
a) Skin
b) Thyroid
c) Bone marrow
d) Gonads

Answer 6

Bone marrow, skin and thyroid (BTS) are anatomical points that have been used for SOMATIC dose measurements. Bone marrow dose is a reasonable indicator of doses to other cancer sensitive internal organs and is a reasonable indicator of somatic effects.

Question 7

Which of the following people must be monitored REGARDLESS of their likely exposure?
a) Operating room staff
b) People who enter a radiation area
c) People who operate mobile x-ray equipment
d) People who enter a high radiation area
e) All hospital personnel

Answer 7

c) People who operate mobile x-ray equipment
d) People who enter a high radiation area

Question 8

Genetically Significant Dose (GSD) is a function of what?

Answer 8

GSD is a function of three parameters: - number of future children
- x-ray examination rate
- mean gonad dose per examination

Question 9

Damage to the CNS from radiation exposure resulting in changes to learning patterns and development can result from radiation exposure during which stage of pregnancy?
(select all that apply)

a) First two weeks of gestation
b) First trimester
c) Second trimester
d) Third trimester

Answer 9

During the later stages of pregnancy (2nd and 3rd trimesters) fetal tissue is more resistant to radiation damage. BUT functional damage can occur, particularly involving the CNS. This may manifest as subtle alterations in learning patterns and development.

(exposure at the earlier stages can lead to genetic defects, spontaneous abortions??)

Question 10

Which factors lead to radiation exposure to the operator?
(select all that apply)

a) Radiation leakage from the x-ray housing
b) Scatter off of the patient
c) Scatter off of the collimator
d) Scatter off of the table top

Answer 10

The chief danger to the operator during fluoroscopic procedures is exposure to the scattered radiation coming primarily from the patient.

Scatter can also come from other sources such as equipment. Additionally, although leakage radiation is generally much less than scatter, it may not be zero and should also be taken into account.

Question 11

Growing tissue that is exposed to radiation most frequently develops
a) Breaks in chromosomes
b) Stoppage of cell division
c) Clumping of chromatin
d) Formation of deformed cells

Answer 11

Stoppage of cell division

may be temporary or permanent

Question 12

What dose of radiation might result in cessation of sperm formation?

Answer 12

40 rads

Question 13

What are the monthly and total pregnancy dose limits for pregnant personnel?

Answer 13

The monthly and total pregnancy dose limits for pregnant personnel is 0.5 mSv and 5 mSv, respectively

or 0.5 rem = 5mSv

Question 14

A skin dose is a good indicator of:
a) Dose to nearby organs
b) Gonadal dose
c) Bone marrow dose
d) Genetic dose
e) Whole body dose

Answer 14

dose to nearby organs.
Skin does not attenuate the x-ray beam significantly and is thought to be a good indicator of underlying organ doses

Question 15

Which is an example of an overhanging shield?
a) Lead apron
b) shaped, contact gonadal shield
c) Lead glass shield that is ceiling supported shield
d) Mobile screen
e) Bucky tray cover

Answer 15

An overhanging shield is one which is supported by the ceiling, such as lead glass or aprons.

Question 16

Which of the following does not directly effect tabletop exposure?
a) Target-to-panel distance
b) Collimation
c) Milliamperage (mA) setting
d) Room lighting

Answer 16

Tabletop exposure rate is dependent on x-ray machine settings and shielding. The light in the room does not directly effect the amount of radiation exposure.

Question 17

How do pocket ionization chambers record radiation exposure?

Answer 17

Pocket ionization chambers discharge a capacitor by ionization of air within a chamber when in the presence of ionizing radiation. The rate of discharge depends on the intensity of the radiation

Question 18

The biological effects of ionizing radiation follow which dose-effect curve?
a) linear, threshold dose-effect curve
b) non-linear, threshold dose-effect curve
c) linear, non-threshold dose-effect curve
d) non-linear, non-threshold dose-effect curve

Answer 18

c) A linear, non-threshold dose-effect curve
Regulatory guidelins are based on a linear non-threshold pattern, which states that any dose, no matter how small, is considered to have some effect. This conservative approach to radiation exposure is needed due to the severe consequences of excessive radiation exposure.

Question 19

What is the purpose of the cumulative manual-reset timer?
a) To protect the patient from prolonged radiation exposure
b) To keep track of fluoroscopy time for reimbursement
c) To allow the machine to cool down
d) To update the patient on the status of the procedure

Answer 19

a) To protect the patient from prolonged radiation exposure

The manual-reset timer serves as a reminder to the operator of how much total exposure time has been used in an effort to reduce patient radiation exposure. The timer must produce an audible signal AND interrupt the x-ray beam when the time limit is reached

Question 20

What is the whole body (total effective dose equivalent) annual occupational dose equivalent limit?

Answer 20

0.05 Sv = 5 rem

Question 21

All of the following have been used for somatic dose measurements EXCEPT:
a) Skin
b) Thyroid
c) Bone marrow
d) Gonads

Answer 21

gonads

Question 22

Why is a single anatomic dose reading NOT representative of the total somatic effect from radiological examinations?
(select all that apply)
a) There is protective shielding.
b) The X-ray beam may be restricted to one area.
c) Radiation doses are not uniformly distributed.
d) None of the above.

Answer 22

A/B/C

The total somatic effect includes the entire body and cannot be captured by a single dose. Shielding, x-ray beam restriction, and nonuniform doses all need to be taken into account when determining somatic effect

Question 23

What is the annual radiation dose limit in mSv for members of the public?

Answer 23

1 mSv = 0.1 rem
(0.001 Sv = 0.1 rem)

OR

0.02 mSv in any one hour

Question 24

According to the California Radiation Control Regulations, what is the limit for occupational whole-body dose equivalent radiation exposure for adults (age older than 18 years)?
a) 5 mSv per calendar quarter
b) 12.5 mSv per calendar quarter
c) 25 mSv per calendar quarter
d) 50 mSv per calendar quarter

Answer 24

The occupational whole-body dose equivalent for persons over 18 years of age is 50 mSv per YEAR (12.5 mSv per QUARTER).

Question 25

Which personnel monitoring device is accurate within 9% of the actual exposure dose? a) Film badge b) Thermoluminescent dosimeter (TLD) c) Pocket chamber d) Audible warning device e) Geiger counter

Answer 25

TLD

Question 26

What is the minimum lead equivalent thickness for a gonadal shield?

Answer 26

0.5mm

Question 27

What bone marrow area is typically exposed when wearing a lead apron? (select all that apply) a) Clavicles b) Skull c) Arms d) Sternum e) Spine f) Pelvis

Answer 27

A/B/C Lead aprons cover about 80% of the active bone marrow of the body. The bone marrow outside the apron is contained primarily in the skull, the arms, and clavicles.

Question 28

What is the best protective eyewear for the operator to utilize during fluoroscopy? a) Polaroid sunglasses b) Lead glass contact lenses c) Lead glass eyeglasses d) Wraparound lead glass eyeglasses

Answer 28

Wraparound lead glass eyeglasses

Question 29

Which long-term effects from radiation exposure are of greater concern from a public health standpoint? (select all that apply) a) Short-term effects b) Genetic effects c) Carcinogenic effects

Answer 29

b) Genetic effects c) Carcinogenic effects Chronic radiation exposure is of great concern to public health because of the possible genetic and carcinogenic effects

Question 30

Examples of stochastic effects of radiation are: (select all that apply) a) Somatic effects b) Carcinogenesis c) Cataracts d) Bone Marrow cell depletion e) Non-malignant skin damage

Answer 30

a) Somatic effects b) Carcinogenesis Stochastic effects refer to the probability of an effect occurring, not the severity. They are a function of radiation dose without a threshold. Examples include somatic effects and carcinogenesis. Nonstochastic (Deterministic) effects of radiation are effects which the severity varies by dose and for which a threshold may exist. Examples include cataracts, non-malignant skin damage, and bone marrow cell depletion.

Question 31

Mobile screens are available in what lead equivalent thickness? a) 0.25 mm b) 0.5 mm c) 1 mm d) 5 mm e) 10 mm

Answer 31

Mobile screens are available in 1.0 mm or 2.0 mm lead equivalent. They are useful for protecting the operator as well as providing a convenient shelf for gloves or small cassettes

Question 32

Geneticists in general agree that most genetic mutations are: a) Harmful b) Beneficial c) Not harmful d) Possibly beneficial

Answer 32

Harmful

Question 33

Operator protection is best achieved by: (select all that apply) a) Wearing a monitoring device (chosen) b) Wearing a lead apron (chosen) c) Standing as far from the patient as possible (chosen)

Answer 33

Operator protection is achieved by wearing a protective lead apron and standing away from the x-ray beam. A monitoring device can tell an operator how much they were exposed, but provides no protection against exposure.

Question 35

Which area is most susceptible to radiation induced cancer? a) Bone b) Gastrointestinal tract c) Female breast d) Hematopoietic tissue

Answer 35

Female breast The most frequently occuring radiation induced cancers in DECREASING order are female breast, thyroid, hematopoietic, lung, and bone.

Question 36

How soon must the State Department of Health be notified if an occupational worker receives an exposure of 0.05 Sv to the skin or extremities? a) Immediately b) Within 24 hours c) Within 30 days d) No notification is needed

Answer 36

d) No notification is needed A shallow-dose equivalent to the skin exceeding 0.50 Sv must be reported within 24 hours. Doses below that do not require notification.

Question 37

What structure does light hit first in the human eye? a) Retina b) Cones c) Lens d) Cornea e) Rods

Answer 37

Light passes through the cornea first. It then passes through the lens (this is the structure that can develop radiation induced cataracts) on its way to the rods and cones, which are located in the back of the eye on the retina.

Question 38

The reading of a personnel radiation device is considered a: a) Whole-body dose b) Somatic dose c) Genetic dose d) Marrow dose e) Shallow dose

Answer 38

a) whole body dose Any personnel radiation monitoring device's reading is considered to be a whole-body radiation dose

Question 39

Scattered radiation incident on the operator during a fluoroscopy procedure is directly proportional to the: a) X-ray tube size b) Collimator setting c) Patient radiation dose d) mA setting e) kVp setting

Answer 39

c) Patient radiation dose The chief danger to the operator during fluoroscopic procedures is exposure to the scattered radiation coming primarily from the patient

Question 40

Which method of gonadal shielding is approved for use in the upright position during fluoroscopy? (select all that apply) a) Shaped, contact shielding b) Shadow shielding c) Flat contact shielding d) Shaped, contact shield in an athletic supporter e) None is needed

Answer 40

A+D Shaped, contact shielding is best because it provides coverage from radiation directly in front of an operator as well as scatter from different angles

Question 41

Which group(s) of people provided early evidence of the potential harmful effects of large dose exposure to ionizing radiation? (select all that apply) a) Surgeons b) Radiologists c) Radium Industry workers (chosen) d) Fluoroscopy Technologists (chosen)

Answer 41

B/C Evidence that harmful effects can result from a large exposure of ionizing radiation is based upon experience of early radiologists and persons working in the radium industry

Question 42

Effects from radiation exposure that occur long after exposure are referred to as: a) Delayed effects b) Long-term effects c) Late effects d) All of the above

Answer 42

D Late, long-term, and delayed effects all refer to effects of radiation exposure that manifest themselves years after the original exposure

Question 43

Whole-body dose means exposure to: (select all that apply) a) Head b) Trunk c) Arms above the elbows d) Arms below the elbows e) Legs above the knees f) Legs below the knees g) Gonads

Answer 43

Everything but d) Arms below the elbows + f) Legs below the knees Whole-body dose refers to exposure to the head, trunk, gonads, arms ABOVE the elbows, and legs ABOVE the knees.

Question 44

Roentgen is a unit of: a) Absorbed dose b) Exposure c) Dose equivalent d) Energy e) Dose rate f) Emitted dose

Answer 44

Exposure Roentgen is a unit of exposure to x-rays.

Question 45

This refers to a radiation dose with a threshold, and with a severity of effect that varies with dose: I. stochastic effect II. nonstochasticeffect III. deterministic effect a) None of the above b) II only c) II & III only d) I & II & III

Answer 45

II & III only Nonstochastic effects are those for which the severity varies with radiation dose and for which there may be a threshold. Deterministic is synonymous with nonstochastic.

Question 46

When reproductive cells are irradiated there may be changes in: (select all that apply) a) Genes (chosen) b) Membrane permeability c) Chromosomes (chosen) d) Ribosomes

Answer 46

A/B/C Genes and chromosomes both contain DNA, and so these may be changed as a result of radiation exposure. Ribosomes do not contain DNA and so does not change with exposure. Membrane permeability can also be effected by radiation damage.

Question 47

Which of the following contrast media reactions are considered moderate? (select all that apply) a) Mild nausea b) Diffuse urticaria c) Nasal congestion d) Facial edema e) Wheezing with hypoxia

Answer 47

b) Diffuse urticaria + d) Facial edema Mild: mild N/V, limited urticaria, limited "itchy" throat, nasal congestion, and sneezing/runny nose. Moderate: protracted N/V, diffuse urticaria, diffuse erythema, facial edema without difficulty breathing, hoarseness without difficulty breathing, or wheezing without hypoxia. Severe: facial edema with difficulty breathing, diffuse erythema with hypotension, laryngeal edema or wheezing with hypoxia, anaphylactic shock.

Question 48

The magnitude of the effect of radiation on a patient is primarily dependent on: a) The total area exposed b) Shielding c) The patient's age d) The tissue type

Answer 48

a) The total area exposed

Question 49

What is the main disadvantage of thermoluminescent dosimeters (TLD)? a) They are heavy b) They have a large measurement error c) They are costly d) Exposures can only be read once

Answer 49

The exposure information is lost during the process of reading a TLD exposure dose and so cannot provide permanent storage

Question 50

Laboratory and clinical methods will generally not show injury until an exposure of ____ rads is reached. a) 10 b) 25 c) 50 d) 100

Answer 50

if ≤ 25 rads, ordinary laboratory or clinical exposure shows NO indications of injury with regards to short-term effects

Question 51

When the x-ray tube is under-the-table, which tabletop material results in the lowest patient exposure? a) Lead b) Carbon fiber c) Aluminum d) Bakelite

Answer 51

Carbon fiber

Question 52

A primary protective barrier is: a) The ceiling b) The floor c) The walls d) The image intensifier assembly

Answer 52

The image intensifier assembly The image intensifier assembly serves as the primary protective barrier. The ceiling, floor and walls are only exposed to secondary (or scattered) radiation and are considered secondary barriers

Question 53

Grids are used in x-ray systems to improve image quality, but can increase the radiation dose to patients and staff by how much? a) 3 to 5 times b) Stays the same c) 1.5 to 2 times d) 5 to 10 times

Answer 53

c) 1.5 to 2 times Antiscatter grids can increase contrast and improve image quality, but can increase the radiation dose by 1.5 to 2 times.

Question 54

The reading of a personnel radiation device is considered a: a) Whole-body dose b) Somatic dose c) Genetic dose d) Marrow dose e) Shallow dose

Answer 54

a) Whole-body dose

Question 55

Why are filters used in film badges? a) To measure doses over a wide range of energies b) To remove low energy radiation c) To determine the number of exposures d) To filter out harmful radiation from reaching the operator

Answer 55

a) To measure doses over a wide range of energies Film badges consist of two essential components: A film holder (usually plastic) with a variety of filters and the packaged film. The purpose of the filters is to permit dose measurement over a wide range of energies. Radiation exposure to the film is accumulated over time and then radiation exposure dose is determined by comparing to a film with a known dose of radiation exposure. Film badges are one way to measure radiation dose, however, there are multiple others (Thermoluminescent dosimeter, pocket ionization chamber, audible warning device). Film badges to not absorb radiation.

Question 56

Biological effects of ionizing radiation that are manifested in offspring are: (select all that apply) a) Delayed effects b) Genetic effects c) Inherited effects d) Cataractogenic effects e) Carcinogenic effects

Answer 56

B+C b) Genetic effects c) Inherited effects Biological effects manifested in offspring of patients exposed to radiation are thought to be a result of mutations in DNA (genetic). These mutations can be passed on to offspring (inherited) during reproduction

Question 57

When should the State be notified If an occupational worker receives an exposure of 0.02 Sv for 3 consecutive calendar quarters? a) Immediately b) Within 24 hours c) Within 30 days d) No notification is required e) Within 72 hours f) Within 1 week

Answer 57

b) Within 24 hours If a worker receives an exposure of 0.02 Sv for 3 consecutive quarters than the worker's total exposure is 0.06 Sv prior to the end of the calendar year. The maximum annual permissible dose for operators is 0.05 Sv. Doses of 0.05 Sv or more must be reported within 24 hours and doses of 0.25 Sv or more must be reported immediately

Question 58

All of the following are disadvantages of using pocket ionization chambers EXCEPT? a) Can be self-read b) Are sensitive to mechanical shock c) Must be calibrated periodically d) Do not provide a permanent record e) Information is lost if over-exposed

Answer 58

a) Can be self-read Pocket ionization chambers allow immediate reading of radiation exposure, which can be a major advantage. Disadvantages include no permanent record, sensitivity to mechanical shock, periodic calibration required, limited dose range, and loss of information if over-exposed

Question 59

Why are filters used in film badges? a) To measure doses over a wide range of energies b) To remove low energy radiation c) To determine the number of exposures d) To filter out harmful radiation from reaching the operator

Answer 59

a) To measure doses over a wide range of energies Film badges consist of two essential components: A film holder (usually plastic) with a variety of filters and the packaged film. The purpose of the filters is to permit dose measurement over a wide range of energies. Radiation exposure to the film is accumulated over time and then radiation exposure dose is determined by comparing to a film with a known dose of radiation exposure. Film badges are one way to measure radiation dose, however, there are multiple others (Thermoluminescent dosimeter, pocket ionization chamber, audible warning device). Film badges to not absorb radiation

Question 60

What happens to a patient's entrance skin exposure (ESE) when the field of view is decreased on the image intensifier? a) Remains the same b) Decreases c) Increases

Answer 60

c) Increases Decreasing the FOV on an II is the principle behind magnification mode. As the voltage is increased to the electrostatic lens, a smaller beam of electrons is sent to the output phosphor with a resulting decrease in minification gain and image brightness. This results in a dimmer image, requiring increased exposure rates, and an increase in patient dose

Question 61

The visual acuity of rods (scotopic vision) is ____ compared to cones (photopic vision). a) Worse b) Better c) The same

Answer 61

a) Worse Cones function in daylight (photopic vision) to perceive color, while rods function at night (scotopic vision) to perceive grays. The visual acuity of cones is better than that of rods, but cones require daylight (photopic) levels of light to function.

Question 62

Which method of gonadal shielding is approved for use in the upright position during fluoroscopy? (select all that apply) a) Shaped, contact shielding b) Shadow shielding c) Flat contact shielding d) Shaped, contact shield in an athletic supporter (chosen) e) None is needed

Answer 62

A+D Shaped, contact shielding is best because it provides coverage from radiation directly in front of an operator as well as scatter from different angles

Question 63

What barrier is required for the walls, floor and ceiling exposed to the primary beam? a) Primary barrier b) Secondary barrier c) Tertiary barrier d) No barrier

Answer 63

a) Primary barrier Any barrier that is exposed to the primary beam is considered a primary barrier and must be sufficient to significantly block the primary beam.

Question 64

Two minutes of fluoroscopic exposure during an upper gastrointestinal study delivers how much estimated skin entrance radiation to a patient? a) Less than 5 rads b) 5-15 rads c) 20-30 rads d) 50-100 rad

Answer 64

b) 5-15 rads A 2-minute upper G.I. tract fluoroscopic study could deliver a skin entrance exposure to the patient as much as 5-15 rads

Question 65

Which of the following is(are) an acceptable personnel monitoring device? (select all that apply) a) Thermoluminescent dosimeter (TLD) b) Audible warning device c) Pocket dosimeter d) Geiger counter e) Film badge

Answer 65

a) Thermoluminescent dosimeter (TLD) e) Film badge Acceptable personnel monitoring devices include film badges and thermoluminsecent dosimeters (TLD). Pocket dosimeters and audible warning devices can be worn in addition to these, but not alone.

Question 66

What is the topic of the Biologic Effects of Ionizing Radiation (BEIR) report VII? a) Development of the linear, non-threshold hypothesis b) Health effects of exposure to Radon c) Health effects of exposure to internally deposited alpha-emitters d) Health risks from exposure to low-level ionizing radiation

Answer 66

D) Health risks from exposure to low-level ionizing radiation The Biologic Effects of Ionizing Radiation (BEIR) report VII concerns is an up to date review of the risks for cancer and other health effects from exposure to low-level ionizing radiation.

Question 67

Somatic changes caused by radiation include: a) Decreased fertility b) Cancer c) Genetic mutations d) Injuries to a fetus

Answer 67

a) Decreased fertility b) Cancer d) Injuries to a fetus Somatic changes include any changes that do not effect the genetic tissue of a patient that can be passed on to future generations. Cancer and Impaired fertility are somatic effects to the patient. Injuries to the developing fetus are considered somatic effects to the fetus

Question 68

here are the filters held in a film badge? a) Ionization chamber b) Film holder c) Backplate d) None of the above

Answer 68

b) Film holder Film badges consist of two essential components: A film holder (usually plastic) with a variety of filters and the packaged film. The purpose of the filters is to permit dose measurement over a wide range of energies. Radiation exposure to the film is accumulated over time and then radiation exposure dose is determined by comparing to a film with a known dose of radiation exposure. Film badges are one way to measure radiation dose, however, there are multiple others (Thermoluminescent dosimeter, pocket ionization chamber, audible warning device). Film badges to not absorb radiation. Syllabus

Question 69

Which cell line is used as an indicator of somatic effects of radiation? a) Muscle b) Bone marrow c) Thyroid d) Skin e) Nerve

Answer 69

Bone marrow is very sensitive to radiation and bone marrow doses are reasonable indicators of doses to other internal organs that are sensitive to cancer (lung, gastrointestinal). Since the mortality associated with these cancers is high, bone marrow dose is used as an indicator of somatic effects of radiation

Question 70

The purpose of the Radiation Control for Health and Safety Act of 1968 was to: (select all that apply) a) Minimize operator exposure b) Minimize patient exposure c) State the laws regarding x-ray use with patients d) Protect radiographers from lawsuits

Answer 70

a) Minimize operator exposure b) Minimize patient exposure The Radiation Control for Health and Safety Act of 1968 was aimed at minimizing patient and operator x-ray exposure, without sacrificing diagnostic diagnostic information

Question 71

What is the half-value layer (HVL)? a) The time it takes for radioactive material to decay to half it's strength b) The thickness of lead necessary to block an entire dose of radiation c) The thickness of absorbing material necessary to reduce the X-ray intensity to half its original value d) The thickness of lead necessary to block half of a dose of radiation

Answer 71

c) The thickness of absorbing material necessary to reduce the X-ray intensity to half its original value The concept of half-value layer (HVL) is important in shielding, where it guides material choice to attenuate x-rays. HVL is defined as the thickness of an absorbing material necessary to reduce the x-ray intensity to half its original value.

Question 72

What is the highest radiation dose film badges can record? a) 500 millirads b) 700 millirads c) 500 rads d) 700 rads

Answer 72

Film badges are sensitive to radiation exposure as low as 10 millirads and as high as 700 rads.

Question 73

Aprons of at least 0.25 mm lead equivalent must be worn if the operator is likely to receive at least what dose of radiation? a) 1 millirad/hr b) 5 millirads/hr c) 10 millirads/hr d) 1 rad/hr e) 2 rads/hr

Answer 73

b) 5 millirads/hr

Question 74

What is the dose equivalent limit to an embryo/fetus during the entire pregnancy for an occupational exposure of a pregnant woman? a) 0.5 mSv b) 5 mSv c) 50 mSv d) 500 mSv

Answer 74

5 mSv The dose to an embryo/fetus during the entire pregnancy should not exceed 5 mSv

Question 75

Which recording system can reduce patient dose up to 95%? a) Video disc recording b) Video tape recording c) Boost fluoroscopy

Answer 75

video disc recording Manufacturers report up to 95% dose reduction with video disc recording.

Question 76

How can you reduce patient radiation exposure during fluoroscopy? (select all that apply) a) Moving the source further away (increasing target-to-panel distance) b) Increasing the mA c) Moving the source closer (decreasing target-to-panel distance) d) Increasing the exposure time e) Using collimation

Answer 76

Moving the source further away an using collimation will REDUCE patient exposure Increasing exposure time, increasing mA, and decreasing target-to-panel distance all INCREASE patient exposure

Question 77

What type of radiation do secondary barriers protect against? (select all that apply) a) Leakage radiation b) Scattered radiation c) Primary radiation d) Useful beam e) Stray radiation

Answer 77

Secondary barriers protect against stray radiation, which includes leakage and scattered radiation

Question 78

This type of personnel monitoring device works because the amount of light emitted by a crystal is proportional to the amount of radiation that was previously absorbed by the crystal? a) Film badge b) Pocket chamber c) Audible dosimeter d) Thermoluminescent dosimeter (TLD) e) Geiger counter

Answer 78

A thermoluminescent dosimeter (TLD) absorbs radiation and can later be heated to emit light that is proportional to the radiation energy absorbed, allowing calculation of radiation exposure

Question 79

Which state of pregnancy is most important for morphological defects in a newborn due to radiation exposure? a) First trimester b) Second trimester c) Third trimester d) First two weeks of gestation

Answer 79

During the first trimester radiation exposure can produce morphological defects in newborns

Question 80

What material are thermoluminescent dosimeters (TLD) made from? a) Zinc sulfide b) Tungsten c) Calcium phosphate d) Lithium Fluoride

Answer 80

d) Lithium Fluoride

Question 81

What is the maximum exposure rate allowed for fluoroscopic equipment manufactured after August 1, 1974, without automatic exposure controls (AEC)? a) 10 rads/minute b) 5 rads/minute c) 2.2 rads/minute d) 1 rad/minute e) 20 rads/minute

Answer 81

b) 5 rads/minute

Question 82

The purpose of the Radiation Control for Health and Safety Act of 1968 was to: (select all that apply) a) Minimize operator exposure b) Minimize patient exposure c) State the laws regarding x-ray use with patients d) Protect radiographers from lawsuits

Answer 82

a) Minimize operator exposure b) Minimize patient exposure The Radiation Control for Health and Safety Act of 1968 was aimed at minimizing patient and operator x-ray exposure, without sacrificing diagnostic diagnostic information

Question 83

The long-term biologic effects of chronic low-dose exposure to radiation a) Are not currently known b) Were evident in the 1890's c) Have accumulated since World War II d) Have been evident since the early 1900's

Answer 83

c) Have accumulated since World War II Most of our current knowledge of the long term biologic effects of radiation has been accumulated since world war II

Question 84

What is the minimum required thickness (lead equivalent) of a primary protective barrier for systems operating above 125 kilovolt peak (kVp)? a) 1.0 mm b) 2.0 mm c) 3.0 mm d) 5.0 mm

Answer 84

b) 2.0 mm The image intensifier assembly serves as the primary protective barrier and must be at least 2 mm of lead equivalent for equipment capable of operating above 125 kVp.

Question 85

This area is defined as one in which an individual could receive a dose equivalent greater than 1 mSv in 1 hour a) Exposure area b) Radiation area c) Ultra high radiation area d) High radiation area

Answer 85

d) High radiation area A "high radiation area" is one in which there exists radiation levels that could result in an individual receiving a dose equivalent in excess of 1 mSv in 1 hour at 30 cm from the radiation source

Question 86

What is the approximate dose to the fetus from an upper-GI examination of a pregnant patient with a total skin exposure of 5 Roentgens? a) 1 millirad b) 100 millirads c) 1 rad d) 50 rads

Answer 86

b) 100 millirads 1 Roentgen = 1 Rad. 1 Rad = 1,000 millirads. 5 Roentgens of skin exposure is equal to 5,000 millirads. The dose to the fetus is approximately 2% of the skin dose. 2% of 5,000 = 0.02 * 5,000 = 100.

Question 87

The contrast on the television monitor should be set so that: a) The darkest object is just below the black level b) The brightest object is just below the black level c) To maximize the visibility of the object, even if there is a large increase in noise d) The bright objects are just below the white level e) The bright objects white out details of the image

Answer 87

a) The darkest object is just below the black level Television monitor contrast is set based on the darkest object on the screen. This allows the remaining objects to also be visible on the screen.

Question 88

Which body area has the largest distribution of fluoroscopic examinations? a) Chest b) Gastrointestinal Tract c) Lower Extremities d) Upper Extremities e) Other

Answer 88

b) Gastrointestinal Tract The gastrointestinal tract has the largest distribution of fluoroscopic examinations, including the barium enema, upper GI series, and KUB.

Question 89

What is the estimated reduction in exposure from diagnostic x-rays that can be achieved without compromising patient benefit? a) 25% b) 50% c) 75% d) 100%

Answer 89

50% Estimates indicate that over 50% of radiation exposure from diagnostic x-rays can eliminated without compromising patient benefit. This highlights the importance of understanding proper use of x-ray equipment

Question 90

Temporary sterility to a woman may result from what dose to the gonads? a) 30 millirads b) 1 rad c) 30 rads d) 100 rads

Answer 90

c) 30 rads Acute doses on the order of 30 rads to the gonads may produce temporary sterility. These doses are not encountered in routine diagnostic radiographic examinations

Question 91

How does the actual radiation exposure compare to the amount recorded by a personnel monitoring device? a) It is always the same b) It is sometimes much higher c) It is usually much less

Answer 91

B) It is sometimes much higher The real exposure an individual receives may be many times the amount recorded if significantly more radiation is received at a location remote from the monitoring device.

Question 92

When the fluoroscopy time limit has been reached, the manual-reset timer must: I. Automatically reset II. Turn off the machine III. Produce an audible signal IV. Interrupt the X-ray beam a) III or IV b) I or III c) II & III d) I, III, & IV

Answer 92

a) III or IV The manual-reset timer has a predetermined time limit of at most 5 minutes and serves as a reminder to the operator of how much total exposure time has been used. The timer must 1) produce an audible signal or 2) interrupt the x-ray beam when the time limit is reached.

Question 93

Increasing the kilovoltage peak (kVp) and decreasing the milliamperage (mA) causes: a) Decreased skin exposure b) Increased skin exposure c) Decreased internal organ exposure d) Increased image contrast

Answer 93

a) Decreased skin exposure High kVp tend to reduce patient dose (decreased skin exposure) because the improved x-ray beam quality allows the use of lower x-ray tube current (mA).

Question 94

What is the estimated female gonadal dose from a barium enema exam? a) 50 millirads b) 80 millirads c) 500 millirads d) 800 millirads

Answer 94

Barium enema (BE) results in approximately 790 millirads (7,900 microGray) dose to female ovaries.

Question 95

Which tissue dose is an indicator of internal organ doses that are sensitive to cancer induction? a) Brain dose b) Bone marrow dose c) Gonadal dose d) Bone dose

Answer 95

b) Bone marrow dose Bone marrow dose is a reasonable indicator of doses to internal organs that are sensitive to cancer induction, such as the lung and GI tract. Since mortality rates from cancer in these organs are high, bone marrow dose is considered a reasonable indicator of somatic effects.

Question 96

Animal experiments have shown that deleterious effects to an embryo can be produced with as little as radiation exposure as ____. a) 1 rad b) 10 rads c) 1 mrad d) 10 mrad

Answer 96

10 rads

Question 97

Scattered radiation incident on the operator during a fluoroscopy procedure is directly proportional to the: a) X-ray tube size b) Collimator setting c) Patient radiation dose d) mA setting e) kVp setting

Answer 97

c) Patient radiation dose

Question 98

Around what acute dose of radiation do cataracts form? a) 5 rads b) 50 rads c) 200 rads d) 1000 rads

Answer 98

c) 200 rads The dose necessary to form cataracts in humans is thought to be on the order of several hundred rads of acute x-rays

Question 99

What is the limit for leakage radiation from a fluoroscopic x-ray tube housing? a) 50 mR at 1 meter b) 100 mR at 1 meter c) 1,000 mR at 1 meter d) 2.2 rad at 1 meter

Answer 99

b) 100 mR at 1 meter

Question 100

This personnel monitoring device discharges a capacitor by the ionization of air when in the presence of radiation: (select all that apply) a) Pocket chamber b) Pocket ionization chamber c) Thermoluminescent Dosimeter d) Audible warning device

Answer 100

a) Pocket chamber b) Pocket ionization chamber Pocket ionization chambers discharge a capacitor by ionization of air within a chamber when in the presence of ionizing radiation. The rate of discharge depends on the intensity of the radiation. They are either self-reading, or are read by a special device. The self-reading versions allow immediate reading of radiation exposure by the operator