Kats mod 7 Rad Protection
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What is the minimum source-to-skin distance for a fixed (stationary) fluoroscope & radiographic unit?
Selected Answer:15 inches 38cm
What is the minimum source-to-skin distance for a mobile fluoroscope & radiographic unit?
Selected Answer:12in 30cm
The secondary protective barrier used in room shielding must be at least how thick?
Selected Answer:1/32 inch lead or equivalent
Primary protective barriers, if in the wall, must extend to what height?
Selected Answer:7 feet
The protective curtain hanging from the fluoro tower must contain at least how much lead equivalent?
The expsoure switch on a portable x-ray machine must be attached to a cord that is at least how long?
Selected Answer:6 feet
Leakage radiation from a diagnostic x-ray may not exceed
Answer: 100 mR per hour @ 1 meter from the housing
To within what percent of the SID must the collimator light and the actual light area be accurate?
An x-ray machine operating at potentials above 70 kVp require how much total tube filtration?
Correct Answer: 2.5 mm Al equivalent
Where should a flat contact shield be placed during a fluoroscopic procedure?
Answer: under the patient at gonadal level
What principle means that radiographer's do what is possible to keep doses to patients and themselves at minimal levels?
What is positive beam limitation?
Selected Answer: collimators automatically limit the field size to the useful area of the detector.
Why does the use of cone increase patient dose?
Correct Answer: mAs must always be increased to make up for the rays attenuated by the cone
From a radiation protection standpoint, what is the purpose of filtration?
Selected Answer:for the removal of low xrays
Define half-value layer
Correct Answer: Amount of filtration that reduces the intensity of the x-ray beam to half of its original value
A fluoroscopy timer must make an audible noise after how much beam-on time?
Selected Answer:5 min
What is a dead-man type switch?
Selected Answer:a foot pedal control switch maned by the radiologist so if the operator were to die or drop dead the exposure would stop.
Table top dose can not exceed what limit?
Selected Answer:10 R/min
What does it mean to have intermittent fluoroscopy?
Selected Answer:to use intermittent activation of fluoroscopic views rather than one long period of x-ray beam-on time. Correct Answer: turn off - turn on; never on @ all time
A lead apron of @ least how much lead equivalent must / shall be worn?
A lead apron of at least 0.25-mm lead equivalent must be worn
Which of the following is not a consideration in determining exposure factors
1-The effective atomic numbers of the tissues involved
2-The desired balance of radiographic density and contrast
3-The type and quality of filtration used
4-The weight of any shielding devices
4 The weight of any shielding devices
How does the use of a grid affect patient dose? Answers:
1-Dramatically reduces patient dose
2-Increases patient dose
3-Has no effect on patient dose
4-Affects patient dose only with repeat radiographs
2 Increases patient dose
How can patient exposure be limited during fluoroscopic procedures?
1-Use protective shields to protect areas not of clinical interest
2-Properly collimate to limit the x-ray beam to only the area of clinical interest
3-Ensure selection of the proper exposure factors
4- All The Above
4- All of the above
When is an embryo-fetus at least risk from radiation exposure?
4-Equal throughout pregnancy
Who is responsible for limiting the x-ray beam during a radiographic examination?
1-The ordering physician
2-The director of radiology
3-The equipment manufacturer
4-he technologist performing the examination
Added filtration for use in the radiographic beam is placed between which of the following?
1-Protective housing and the collimator
2-Patient and the receptor
3-Table and the patient
4-None of the above
A wedge compensating filter is often used for imaging which of the following?
What is the major disadvantage of a shadow shield?
4-It cannot be used during fluoroscopy
In the design of protective structural shielding, what type of radiation is most hazardous and most difficult to protect against?
3-leakage from the x-ray tube
What is the best location for the control panel exposure switch?
1-Either stationary on the control panel or on a short cord so that it can be used only from within the control booth
2-On a short cord directly outside the door to the room where the radiographic equipment is located
3-On a very long cord outside the room where the radiographic equipment is located
4-On the wall next to the door inside the room where the radiographic equipment is located
When considering the occupancy of rooms and areas, what does general public refer to?
3-Personnel who do not work with radiographic equipment
4- All The above
Why are secondary barriers always given a use factor of 1?
1-Scatter radiation and leakage radiation are always present when the tube is energized
2-The primary beam is not directed at them
3-They are constructed of less-protective material than are primary barriers
4-It is impossible to accurately calculate use, so 1 is used as a safety facto
What are primary protective barriers?
1-Those at which the primary beam is directed
2-Those in the waiting room
3-Those in areas occupied by imaging personnel
4-Those bordering other occupied space
What is the most common protective barrier material used in primary barriers?
2-Multiple layers of gypsum board
3-Lead sheets bonded to wood or sheet rock
Who is the best choice when someone is needed to hold a patient during a radiographic exam?
1-Any person who has been trained in the radiologic sciences
3-A young person within reproductive years
4-An older relative or friend
During a mobile radiographic examination, if the factors of distance and shielding are equal, where should the radiologic technologist stand in relation to the primary beam scattering object line?
1-At a 25-degree angle
2-At a 90-degree angle
3-At a 45-degree angle
4-At a 75-degree angle
When are Bucky slot covers and protective curtains used?
1-During all radiographic procedures
2-During mammographic procedures
3-During mobile radiographic procedures
4-During fluoroscopic procedures
The cumulative timer is used in fluoroscopy to ensure the radiologic technologist is aware of which of the following?
1-The total beam on time
2-The total time per week the unit is used
3-The exposure used
4-His/her total exposure
It is the responsibility of a female radiologic technologist who is planning a pregnancy or becomes pregnant to inform her supervisor of that fact at which of the following times?
1-As soon as she finds out she is pregnant
2-Before the end of the first trimester of pregnancy
3-Before the end of the second trimester of pregnancy
4-When she decides she wants to have children
Why are additional protective measures required in fluoroscopic procedures?
1-The risk of exposure in fluoroscopic procedures is higher than in most other radiographic procedures
2-Patients must always be immobilized by the radiation worker during the procedure
3-Fluoroscopic procedures are rare
4-Most radiographers are unfamiliar with fluoroscopic procedures
When should lead-equivalent gloves of 0.25 mm lead or equivalent be worn to protect the hands of the radiologic technologist?
1-When the hands might be in the x-ray beam
2-Whenever mobile radiographic equipment is used
3-During all radiographic procedures
4-During all fluoroscopic procedures
If there are concerns about maintaining the sterility of a wound / area during a radiographic exam, which device can be used?
1-flat contact shield
3-shaped contact shield
n most cases, control booth barriers in fixed radiographic rooms are built with primary barrier walls?
True or False
In terms of occupacny factor, parking lots, elevators and stairways are considered to be?
In determining barrier thickness, what does the use factor respresent?
1-the use of the space behind the primary barrier
2-the fractional amount of time the primary beam is energized and directed at a barrier
3-the direction of the control booth barrier in relation to the primary beam
4-the direction of the scatter radiation from the primary beam
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