Question 1

The dose equivalent limits for radiation workers are based on the radiation received from what source(s)?

Accepted Answer

Because patients and workers exposed to radiation are at risk for biologic effects,limits must be set to ensure safe practice for both patients and radiation workers.Dose measurement for radiation workers is limited exclusively to occupational exposure.The annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem).

Question 2

Which of the following is a principle of the ALARA concept?

Accepted Answer

The concept of ALARA-as low as reasonably achievable-is used to guide radiation protection practices when performing examinations.This principle applies to both patients and coworkers.

Question 3

In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed?

Accepted Answer

Because complete energy absorption takes place in photoelectric interactions,this constitutes the greatest hazard to patients in diagnostic radiography.Compton scattering contributes most to radiation worker exposure,and Bremsstrahlung and characteristic interactions are not x-ray photon interactions.

Question 4

With regard to the ALARA principle,the responsibility of the radiographer is to

Accepted Answer

The benefit to the patient from performing medical imaging procedures must outweigh the risk of possible biologic damage.Current studies indicate that an individual's dose should be kept as low as reasonably achievable (ALARA).

Question 5

Acute radiation syndrome manifests in four major stages.In what order do these stages occur?

Accepted Answer

The total-body response of any organism to radiation depends on the effect on all the systems of the body.This response,known as acute radiation syndrome,occurs only when the organism is exposed fully (total body)to an external source of radiation given in a few minutes.Three general stages of response exist for each acute radiation syndrome.The first is the prodromal stage.The second stage is the latent period,in which the organism feels well;however,during this time,the body is undergoing biologic changes that will lead to the final period,the manifest stage.Now the organism feels the full effects of the exposure,leading to either recovery or death.

Question 6

Which of the following personnel radiation monitors will provide a near-immediate reading of radiation exposure,if necessary?

Accepted Answer

The pocket dosimeter is used when an immediate reading of occupational dose is desired;however,it is subject to false readings and does not provide a permanent record.Pocket dosimeters are not commonly used to monitor exposure to medical imaging personnel.

Question 7

The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are
1)highly mitotic.
2)undifferentiated.
3)mature cells.

Accepted Answer

The law of Bergonie and Tribondeau states that the mitotic activity and specific characteristics of each cell affected how the cell exhibited radiation damage.Cells are most sensitive to radiation during active division,when they are primitive in structure and function (undifferentiated).

Question 8

Protective devices such as lead aprons are intended to protect the user from _____ radiation.
1)scattered and secondary
2)primary
3)remnant
4)latent

Accepted Answer

The radiographer must use shielding whenever time and distance alone cannot satisfactorily protect the worker.Exposure to radiation workers is generally from secondary and scatter interactions and should never be from primary radiation.

Question 9

The radiation a person receives from the sun (cosmic radiation)is categorized as

Accepted Answer

The two basic sources of ionizing radiation exposure are natural (or background)radiation and human-made (artificial)radiation sources.Background sources occur spontaneously in nature and can be affected by human activity.These forms include cosmic radiation from the sun and other planetary bodies and naturally occurring radioactive substances present on earth (e.g.,uranium and radium),which can be inhaled or ingested through food,water,or air (radon).

Question 10

For a pregnant radiographer who declares her pregnancy to the employer,a second personnel monitoring device is provided.The purpose of this additional monitor is to ensure that the monthly equivalent dose to the embryo or fetus does not exceed _____ mSv (_____ rem).

Accepted Answer

The dose limit is 0.5 rem (5 mSv)for a declared pregnant woman the duration of her pregnancy.In addition,the NCRP recommends that,when pregnancy is known,a limit of 0.05 rem (0.5 mSv)per month should apply.

Question 11

Nausea is principally associated with the

Accepted Answer

Three general stages of response exist for each acute radiation syndrome.The first is the prodromal stage,commonly referred to as the nausea,vomiting,and diarrhea (NVD)stage.

Question 12

When laser light stimulates the sensing material in an optically stimulated luminescence dosimeter (OSL),the

Accepted Answer

The Luxel OSL dosimeter is the most common method used to monitor personnel exposure.To determine the individual's exposure,the aluminum oxide is exposed to a laser light,which stimulates the aluminum oxide after use,causing it to become luminescent in proportion to the amount of radiation exposure,which determines the occupational worker's exposure.

Question 13

The material commonly used for shielding against radiation exposure in protective aprons and gloves is

Accepted Answer

Shields are made of lead,which has an atomic number of 82.Lead absorbs x-rays through the process of photoelectric effect,thereby minimizing patient exposure.

Question 14

The radiographic beam should be collimated so that it is _____ the image receptor.

Accepted Answer

The radiographer always must restrict the primary beam to the anatomic area of interest,never exceeding the size of the image receptor used to capture the information.

Question 15

The photon interaction that results in the highest patient exposure is _____ interactions.

Accepted Answer

Because complete energy absorption takes place in photoelectric interactions,this constitutes the greatest hazard to patients in diagnostic radiography.

Question 16

The function of an x-ray beam filter in diagnostic radiology is to

Accepted Answer

Filtration material in the path of the x-ray beam absorbs the low-energy x-rays that only add to the patient's entrance dose.Eliminating their presence in the primary beam reduces patient entrance skin exposure (ESE).Aluminum is the most common material used in filtration.

Question 17

A given dose of radiation generally has the greatest potential for damage in tissues that have

Accepted Answer

To study a cell's response to radiation,a method of classification according to sensitivity was developed by Bergonie and Tribondeau in 1906.Cells are most sensitive to radiation during active division,when they are primitive in structure and function.Cells with a high rate of mitosis are more radiosensitive.

Question 18

If a technologist stands 2 m from an x-ray tube and receives an exposure rate of 4 mR/hr,the exposure rate would be _____ mR/hr if the person stands 4 m from the x-ray tube.

Accepted Answer

Distance is the best measure of protection for an occupational worker.The principle of the inverse square law states that the intensity of radiation varies inversely with the square of the distance.Doubling the distance between the radiographer and the source of radiation reduces the exposure by a factor of 4 (now 11ea2c74_8b15_2b05_a5cd_218c46971a64_TB1369_11 the dose at the original distance).

Question 19

Which action of ionizing radiation is most prevalent and most harmful to the human body?

Accepted Answer

Because cells are approximately 80% water,indirect action occurs when water molecules are ionized.This action produces chemical changes (free radicals)within the cell that alter the internal environment,injuring the cell,and can result in eventual cell death.With x-radiation and gamma radiation,the vast majority of cellular damage is the result of indirect hits.

Question 20

A woman who is 3 months' pregnant has been in a motor vehicle accident.The emergency department physician suspects there is injury to her cervical spine and thus feels justified in ordering an x-ray examination to aid in determining the extent of the patient's injury.Because the patient is pregnant,the radiographer should
1)select the lowest exposure factors that will produce a diagnostically useful radiograph.
2)adequately and precisely collimate the radiographic beam to include only the anatomic area of interest.
3)shield the patient's lower abdomen and pelvic region with a suitable protective contact shield.

Accepted Answer

Radiographing pregnant patients requires special attention to protection.The principle of ALARA always prevails,and in doing so,the exposed anatomy should be as small as clinically possible.Additionally contact shielding should be used by placing lead shielding material over the reproductive organs (gonads)of the patient whenever they are within 4 to 5 cm of the primary beam.

Quiz 9: Basic Radiation Protection and Radiobiology

The dose equivalent limits for radiation workers are based on the radiation received from what source(s) ?

Which of the following is a principle of the ALARA concept?

In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed?

With regard to the ALARA principle,the responsibility of the radiographer is to

Acute radiation syndrome manifests in four major stages.In what order do these stages occur?

Which of the following personnel radiation monitors will provide a near-immediate reading of radiation exposure,if necessary?

The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are 1) highly mitotic. 2) undifferentiated. 3) mature cells.

Protective devices such as lead aprons are intended to protect the user from _____ radiation. 1) scattered and secondary 2) primary 3) remnant 4) latent

The radiation a person receives from the sun (cosmic radiation) is categorized as

For a pregnant radiographer who declares her pregnancy to the employer,a second personnel monitoring device is provided.The purpose of this additional monitor is to ensure that the monthly equivalent dose to the embryo or fetus does not exceed _ mSv (_ rem) .

Nausea is principally associated with the

When laser light stimulates the sensing material in an optically stimulated luminescence dosimeter (OSL) ,the

The material commonly used for shielding against radiation exposure in protective aprons and gloves is

The radiographic beam should be collimated so that it is _____ the image receptor.

The photon interaction that results in the highest patient exposure is _____ interactions.

The function of an x-ray beam filter in diagnostic radiology is to

A given dose of radiation generally has the greatest potential for damage in tissues that have

If a technologist stands 2 m from an x-ray tube and receives an exposure rate of 4 mR/hr,the exposure rate would be _____ mR/hr if the person stands 4 m from the x-ray tube.

Which action of ionizing radiation is most prevalent and most harmful to the human body?

Quiz 9: Basic Radiation Protection and Radiobiology

The dose equivalent limits for radiation workers are based on the radiation received from what source(s) ?

Which of the following is a principle of the ALARA concept?

In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed?

With regard to the ALARA principle,the responsibility of the radiographer is to

Acute radiation syndrome manifests in four major stages.In what order do these stages occur?

Which of the following personnel radiation monitors will provide a near-immediate reading of radiation exposure,if necessary?

The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are 1) highly mitotic. 2) undifferentiated. 3) mature cells.

Protective devices such as lead aprons are intended to protect the user from _____ radiation. 1) scattered and secondary 2) primary 3) remnant 4) latent

The radiation a person receives from the sun (cosmic radiation) is categorized as

For a pregnant radiographer who declares her pregnancy to the employer,a second personnel monitoring device is provided.The purpose of this additional monitor is to ensure that the monthly equivalent dose to the embryo or fetus does not exceed _____ mSv (_____ rem) .

Nausea is principally associated with the

When laser light stimulates the sensing material in an optically stimulated luminescence dosimeter (OSL) ,the

The material commonly used for shielding against radiation exposure in protective aprons and gloves is

The radiographic beam should be collimated so that it is _____ the image receptor.

The photon interaction that results in the highest patient exposure is _____ interactions.

The function of an x-ray beam filter in diagnostic radiology is to

A given dose of radiation generally has the greatest potential for damage in tissues that have

If a technologist stands 2 m from an x-ray tube and receives an exposure rate of 4 mR/hr,the exposure rate would be _____ mR/hr if the person stands 4 m from the x-ray tube.

Which action of ionizing radiation is most prevalent and most harmful to the human body?

For a pregnant radiographer who declares her pregnancy to the employer,a second personnel monitoring device is provided.The purpose of this additional monitor is to ensure that the monthly equivalent dose to the embryo or fetus does not exceed _ mSv (_ rem) .