safety1 Flashcards - Easy Notecards

Which of the following are recommended to prevent radiation exposure to patients in early pregnancy?

1. Ask patient the date of her last menstrual period
2. Posters stating "tell the radiographer if you are pregnant"
3. Ask patient if there is any chance she could be pregnant

1,2,3

Which of the following publications recommends limits of exposure to ionizing radiation?

A. NCRP #100 B. NCRP #102 C. NCRP #105 D. NCRP #116

D. NCRP #116

Which of the following devices alerts the radiologist that 5 minutes of fluoroscopy has elapsed?

A. Phototimer B. Cumulative timer C. Synchronous timer D. Mechanical timer

B. Cumulative timer

A secondary barrier protects the technologist from which of the following types of radiation?

A. Stem radiation B. Primary radiation C. Scatter radiation D. Gamma radiation

scatter radiation

How far must a radiographer stand back during a mobile radiographic exposure?

A. 1 meter B. 2 meters C. 3 meters D. 4 meters

2meters

Which of the following characteristics makes lead such an excellent protective barrier?

1. High density
2. High atomic number
3. High absorption coefficient
A. 1 only B. 1 & 3 only C. 2 & 3 only D. 1, 2 & 3

D. 1, 2 & 3

What is the effective dose limit a radiography student may receive in one year if he/she is under 18 years old?

A. 1 mSv B. 5 mSv C. 10 mSv D. 50 mSv

1msv

The time it takes for a radioactive material to have 1/2 of its atoms disintegrate is known as what?

A. Lethal dose B. Half-life C. Degree of disintegration D. Specific ionization

half-life

Which of the following is a major disadvantage of a film badge as a radiation monitoring device?

A. Radiation types cannot be determined B. Immediate readings are not available C. Must be changed monthly D. They are grossly inaccurate

Immediate readings are not available

What is the equivalent dose limits that the hands and feet may receive?

A. 200 mSv B. 300 mSv C. 400 mSv D. 500 mSv

500msv

The Geiger counter is capable of detecting which of the following type(s) of radiation?

1. Alpha particles
2. Beta particles
3. Gamma rays

1,2,3

There are two national bodies that set standards for radiography. Which of these is one of them?

A. National Council on Radiation Protection & Measurements

B. Department of Commerce

C. National Bureau of Standards

D. Food and Drug Administration

A. National Council on Radiation Protection & Measurements

The equivalent dose limits for radiation workers is based on the radiation received from what sources?

A. Background radiation B. Medical imaging C. Occupational exposure D. Radiation fallout

Occupational exposure

Which of the following is a radiation survey instrument?

A. Gamma camera B. Cutie pie C. Pocket dosimeter D. Thermoluminescent dosimeter

cutie pie

A recommendation that is to be applied when practical is indicated by the use of which of these terms?

A. Can B. May C. Shall D. Should

should

What is the equivalent dose limits for the hands of a technologist?

A. 50 mSv/year

B. 250 mSv/year

C. 500 mSv/year

D. 750 mSv/year

C. 500 mSv/year

The fact that some materials can store energy, then emit light when heated, is the principle that is used for which of these?

A. Ion detector B. Thermoluminescent dosimeter C. Rate meter D. Proportional spectrometer

B. Thermoluminescent dosimeter

A recommendation that is necessary to meet the accepted standards is indicated by the use of which term?

A. Can B. May C. Shall D. Should

shall

Radiation that leaves the tube housing by any means other than through the window is called what?

A. Primary B. Scatter C. Leakage D. Remnant (exit)

leakage

e following radiation monitoring devices is considered to be the most accurate?

A. Film badge

B. Ring badge

C. Optically stimulated luminescence dosimeter (OSL)

D. Thermoluminescent dosimeter (TLD)

Optically stimulated luminescence dosimeter

Radiation that changes direction as it passes through a material is called what?

A. Secondary B. Scatter C. Leakage D. Remnant (exit)

scattered

A radiographer will receive most of his/her occupational exposure from which of these types of radiation?

A. Primary radiation B. Scatter radiation C. Remnant (exit) radiation D. Gamma radiation

scattered

Which of the following is the unit of exposure dose of gamma or x rays?

A. Gray B. Joule C. Sievert D. Coulomb per kilogram

D. Coulomb per kilogram

How does the energy of scatter radiation compare to that of the primary beam?

A. Less energy B. More energy C. Equal energy D. Doubled energy

less energy

Which of the following definitions describes equivalent dose limits?

A. The maximum dose a body can tolerate

B. A dose that is not expected to produce significant effects

C. The dose a worker will receive/year

D. The maximum dose a radiation monitor records

B. A dose that is not expected to produce significant effects

Patient dose during fluoroscopy can be minimized by which of the following?

1. Decrease tube to tower distance
2. Restrict beam size
3. Increase fluoroscopic milliamperage
A. 1 only B. 2 only C. 3 only D. 1 & 3 only

2. Restrict beam size

(Restricting the beam to just the area of interest is good practice for fluoroscopy as well as radiography.)

Which of the following has the greatest effect on the amount of radiation exposure to the patient?

A. Focal spot size B. SID C. Size of exposed area D. Type of grid (linear or crossed)

Size of exposed area

-Exposure means "being subjected to radiation". The greater the area, the greater the patient is "being subjected to radiation".

Which of the following will reduce radiation exposure to the patient if done by the radiologist during a fluoroscopic study?

A. Magnifying the fluoroscopic image B. Intermittent exposures C. Using the grid D. Increasing the field of view

B. Intermittent exposures

If 2 mm Al is added to an x-ray beam that has a HVL of 2 mm Al, how much will the exposure be reduced?

A. 25% B. 50% C. 75% D. 95%

50%

Which type of gonadal shielding could be used for a patient having an exam requiring a sterile field?

A. Lead sheet B. Lead apron C. Shadow shield D. Pseudo shield

shadow shield

-A shadow shield is mounted on the tube and positioned in the primary beam to cast a "shadow" on the patient. Physical touching of the patient is not necessary.

Which of the following will NOT have an effect on patient dose?

A. Filtration B. SID C. Focal spot size D. kVp

focal spot size

-The size of the focal spot is very important in controlling recorded detail on a radiograph, but it has no affect on the quantity of x rays reaching the patient.

Which of the following will reduce exposure to the patient as well as improve image contrast?

A. Increase grid ratio B. Beam restriction C. Increase kVp D. Decrease SID

beam restriction

-Beam restriction (collimation) will produce less scatter radiation

The source-to-skin distance in stationary fluoroscopy must NOT be less than how many inches?

A. 6 B. 12 C. 15 D. 24

NCRP #102 states that kilovoltage, filtration and source-to-skin distance should be as large as practical. The source-to-skin distance for stationary fluoroscopy shall not be less than 15" (38 cm).

The source-to-skin distance in mobile fluoroscopy must NOT be less than how many inches?

A. 6 B. 12 C. 24 D. 36

-NCRP #102 states that kilovoltage, filtration and source-to-skin distance should be as large as practical. The source-to-skin distance for mobile fluoroscopy shall not be less than 12" (30 cm).

Which of the following signals is needed to indicate that a radiation exposure has been made?

A. Laser light B. Ultraviolet light C. High frequency sound wave D. Audible sound and visible light

D. Audible sound and visible light

-Whenever an exposure is made there has to be an audible sound so the radiographer can watch the patient and still know an exposure was made. A visible indicator is also required.

The quality of an x-ray beam can be measured by which of the following methods?

A. Rate meter B. Sensitometry C. Half-value layer (HVL) D. Spinning top

-. Half-value layer (HVL)

-Quality refers to the energy of the x-ray beam. A rate meter measures the quantity (number) of x rays, but the HVL indicates the beams energy.

The function of a beam filter is to remove which of the following from the x-ray beam?

A. Secondary radiation B. Scatter radiation C. Low energy radiation D. High energy radiat

C. Low energy radiation

Low energy x rays have no potential except to harm the patient. That is why it is important to filter them out of the beam before they reach the patient.

Which of the following are advantages of using dynamic flat-panel detectors for digital fluoroscopy compared to image-intensified fluoroscopy?

1. Rectangular image
2. Post-processing of images
3. Better contrast resolution

-Collimation can be smaller when it is not necessary to compensate for the image-intensifier's circular image. Post-processing and contrast resolution are the main advantages of digital fluoroscopy.

Which of the following could result from excessive radiation exposure to a fetus during the first trimester?

1. Prenatal death
2. Neonatal death
3. Congenital abnormalities

-An exposure of 10 rem in the 1st two weeks can result in prenatal death. Neonatal death would only result from large doses during the 2-8 weeks. 10 rem during 2-8 weeks can cause abnormalities.

Which of the following methods is used to determine if an x-ray tube has adequate filtration?

A. Read tube specifications B. Physical examination of tube C. Visual inspection of tube D. Half-value layer (HVL) measurement

D. Half-value layer (HVL) measurement

-A half-value layer test is the accepted method for determining beam filtration. Title 21 of the Code of Federal Regulations lists minimum HVL's for various tube potentials.

Which of the following filters would produce an x-ray beam with the highest average photon energy?

A. 1 mm Al B. 2 mm Al C. 3 mm Al D. 4 mm Al

4mm AI

-The thicker 4 mm Al filter would filter out more low energy x rays, leaving a beam with only high energy photons.

When should gonadal shielding be used on a patient?

1. If the patient is of a reproductive age or younger
2. If the shield will not interfere with the exam
3. If the gonads lie in or near the primary beam

Which of the following are disadvantages of using a flat piece of lead for gonadal shielding?

1. Cannot be used for erect views
2. Difficult to keep in place
3. Is not very useful for fluoroscopy

Which of the following relates to the equivalent dose limits for a non-radiation worker?

A. 1/10 that of a radiation worker B. 1/2 that of a radiation worker C. The same as a radiation worker D. Twice that of a radiation worker

This would equal 5.0 mSv (.5 rem).

-This would equal 5.0 mSv (.5 rem).

Which of the following will NOT reduce the amount of exposure to the patient?

A. Higher grid ratio B. Proper collimation C. Beam filtration D. Use of intensifying screens

A. Higher grid ratio

-Using a grid always requires more exposure to the patient than non-grid techniques

What is the equivalent dose limit for an embryo-fetus?

A. .1 mSv/month B. .5 mSv/month C. 1.5 mSv/month D. 5.0 mSv/month

.5 mSv/month C

Standards state that the exposure in air from fluoroscopic equipment shall not exceed how many Coulomb/kg/minute?

A. 1.29 x 10-3 Coulomb/kg B. 2.58 x 10-3 Coulomb/kg C. 3.87 x 10-3 Coulomb/kg D. 5.16 x 10-3 Coulomb/kg

- B. 2.58 x 10-3 Coulomb/kg

Most fluoroscopic equipment is calibrated to emit 2 R/minute/mA. Since fluoroscopic mA is usually between 3-5 mA, if calibrated properly, it could not exceed 10 R/minute even at maximum output.

Which of the following refers to the x-ray beam after it has passed through the beam restricting device?

A. Primary beam B. Remnant (exit) beam C. Secondary beam D. Stem beam

A. Primary beam

-Primary radiation is produced in the tube. The radiation that passes through the window and beam restricting device is called the primary beam.

Automatic exposure rate control (AERC) is designed to compensate for changes in which of the following?

A. Examination time B. Technique selection C. Patient positioning D. Patient dose

Patient positioning

-As the patient is moved and repositioned, the anatomical areas allow more or less x rays through. This changes the brightness of the fluoroscopic image. The AERC automatically changes the mA or kVp settings to adjust for these changes in brightness so the image is always easy to view.

Which of the following are reasons for using beam restricting devices?

1. Reduce scatter radiation
2. Reduce patient exposure
3. Improve image contrast

Which of the following types of beam restricting devices is considered the best at reducing patient exposure?

A. Cone B. Diaphragm C. Collimator An extension cylinder produces a round beam. The area of a circle will be less than the area of a square collimator covering the same anatomical part

- Extension cylinder

-An extension cylinder produces a round beam. The area of a circle will be less than the area of a square collimator covering the same anatomical part

Which of the following situations would cause the greatest skin dose to a patient?

A. Short SID B. Long SID C. Small focal spot size D. Highest practical kilovoltage

short SID

-The shorter the distance, the more low energy x rays will reach the patient. It is not recommended to use an SID of less than 40" for radiography.

A .5 mm lead gonadal shield will reduce female gonadal exposure by approximately what percentage?

A. 25% B. 50% C. 75% D. 99%

-75%

A .5 mm lead gonadal shield will prevent 75% of the useful beam from reaching the gonad

What is the purpose of fluoroscopy?

A. To view static anatomy B. To view dynamic anatomy C. To view transaxial anatomy D. To view internal organs

-B. To view dynamic anatomy

-The primary purpose of fluoroscopy is to view dynamic (moving) anatomy. The radiologist can make a diagnosis of the motility (movement) of the structures being viewed. This is why radiographers cannot do fluoroscopy, because they are not allowed to diagnose.

What is the primary purpose of beam filtration?

A. Improve radiographic contrast B. Protect patient from low energy x rays C. Produce uniform densities in the image D. Increase visibility of detail

Protect patient from low energy x rays

-inherent or added filtration placed in the beam absorbs low-energy x rays that would otherwise be absorbed by the patient.

Which of the following describes the fluoroscopic system designed to maintain a constant image brightness?

A. Automatic exposure rate control (AERC) B. Automatic exposure control (AEC) C. Automatic collimation D. Anatomically programmed radiography

-A. Automatic exposure rate control (AERC)

Automatic exposure rate control (AERC) adjusts for changes in brightness during fluoroscopy. The reason this is required is because it is quicker than doing it manually and therefore, reduces patient exposure.

Which of the following examinations would NOT allow male gonadal shielding?

A. Intravenous urogram B. Pelvis examination C. Knee arthrogram D. Voiding cystourethrogram

- Voiding cystourethrogram

The male testes should be shielded for an IVU or pelvis exam; a gonadal shield would probably get in the way during a voiding cystourethrogram.

To prevent leakage radiation from exposing the patient, an x-ray tube must have how much protective lead?

A. 1.5 mm B. 2.5 mm C. 3.5 mm D. 4.5 mm

1.5mm

-X rays that are not in the primary beam are called leakage radiation. The tube housing contains at least 1.5 mm of lead to absorb this leakage radiation.

The dose rate at the table top during fluoroscopy cannot exceed _______ R per minute.

A. 2 B. 5 C. 7 D. 10

-Most fluoroscopy tubes are calibrated to produce 2R/mA/minute. For the average patient, 1 - 3 mA is required to produce an adequate image. The average patient receives 2 - 6 R/min.

How fast can dynamic flat-panel detectors, used in digital fluoroscopy, capture and display an image?

A. 10 - 20 ms B. 30 - 50 ms C. 50 - 70 ms D. 75 - 90 ms

-These speeds are necessary to capture all of the motion.