What is the minimum source-to-skin distance for a fixed (stationary) fluoroscope & radiographic unit?
15 inches 38cm
What is the minimum source-to-skin distance for a mobile fluoroscope & radiographic unit?
12in 30cm
Primary protective barriers, if in the wall, must extend to what height?
7 feet
The protective curtain hanging from the fluoro tower must contain at least how much lead equivalent?
25mm
The expsoure switch on a portable x-ray machine must be attached to a cord that is at least how long?
6 feet
Leakage radiation from a diagnostic x-ray may not exceed
100 milliroentgens in 1 hour
To within what percent of the SID must the collimator light and the actual light area be accurate?
2%
An x-ray machine operating at potentials above 70 kVp require how much total tube filtration?
2 mm of al
Where should a flat contact shield be placed during a fluoroscopic procedure?
at gonadal area under the patient
What principle means that radiographer's do what is possible to keep doses to patients and themselves at minimal levels?
ALARA
What is positive beam limitation?
collimators automatically limit the field size to the useful area of the detector.
Why does the use of cone increase patient dose?
because mAs must be increased to To compensate for this loss, the number of x-rays generated when using a cone
From a radiation protection standpoint, what is the purpose of filtration?
for the removal of low xrays
Define half-value layer
filtration that reduces the intencity of a xray beam to hlf its original streangth
A fluoroscopy timer must make an audible noise after how much beam-on time?
5min
What is a dead-man type switch?
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?
10 R/min
What does it mean to have intermittent fluoroscopy?
to use intermittent activation of fluoroscopic views rather than one long period of x-ray beam-on time.
A lead apron of @ least how much lead equivalent must / shall be worn?A lead apron of how much lead equivalent should be worn?
at least 0.25 mm or 0.5 mm equivalents of lead
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
How does the use of a grid affect patient dose?
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
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 of the above
4
When is an embryo-fetus at least risk from radiation exposure?
1-First trimester
2-Second trimester
3-Third trimester
4-Equal throughout pregnancy
3
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-The technologist performing the examination
4
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
1
A wedge compensating filter is often used for imaging which of the following?
1-Chest
2-Foot
3-Head
4-Sinuses
2
What is the major disadvantage of a shadow shield?
1-Cost
2-Discomfort
3-Inconvenience
4-It cannot be used during fluoroscopy
4
In the design of protective structural shielding, what type of radiation is most hazardous and most difficult to protect against?
1-Scatter radiation
2-Leakage from the x-ray tube
3-Secondary radiation
4-Primary radiation
4
What is the best location for the control panel exposure switch?
1-On a short cord directly outside the door to the room where the radiographic equipment is located
2-On a very long cord outside the room where the radiographic equipment is located
3-On the wall next to the door inside the room where the radiographic equipment is located
4-Either stationary on the control panel or on a short cord so that it can be used only from within the control booth
4
When considering the occupancy of rooms and areas, what does general public refer to?
1-Visitors
2-All of the above
3-Patients
4-Personnel who do not work with radiographic equipment
2
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 factor
1
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
1
What is the most common protective barrier material used in primary barriers?
1-Wood
2-Multiple layers of gypsum board
3-Lead sheets bonded to wood or sheet rock
4-Lead glass
3
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
1
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
2-A radiographer
3-A young person within reproductive years
4-An older relative or friend
4
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
2
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
4
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
1
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
1
Why are additional protective measures required in fluoroscopic procedures?
1-Patients must always be immobilized by the radiation worker during the procedure
2-Fluoroscopic procedures are rare
3-Most radiographers are unfamiliar with fluoroscopic procedures
4-The risk of exposure in fluoroscopic procedures is higher than in most other radiographic procedures
4
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
1
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
2-gonad shield
3- shaped contact shield
4-shadow shield
4
In most cases, control booth barriers in fixed radiographic rooms are built with primary barrier walls
true or false
false
In terms of occupacny factor, parking lots, elevators and stairways are considered to be
1-controlled areas
2-un controlled areas
2
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