RECIT AND QUIZZES Flashcards
To keep it centered in the x-ray tube
charannn walang sagot
It is concerned with providing occupational radiation protection and minimizing radiation dose to the public
Health Physics
It is to ensure proper alignment of the x-ray beam and the IR.
Beam Alignment
What is the lead equivalent for bucky slot cover
0.25 mm Pb
It is the product of the maximum mA and the number of x-ray examinations performed
Workload
It is a process of removing low energy rays result in a lower patient dose
Filtration
What is the best way to reduce the production of scattered radiation?
Collimate
What is the concept of ALARA
As Low As Reasonably Achievable - to less the radiation to the patient
What is the single most important scattering object in both radiography and fluoroscopy
Patient
Give 3 cardinal principles
Time, Distance and Shielding
Define controlled area
Area occupied primarily by radiology personnel and patients
What type of collimator will automatically restrict the x-ray beam w/the size of the image cassette for the image receptor
Positive Beam Limitation (PBL)
What is the 2 sources of secondary radiation
Scatter and Leakage Radiation
What is the minimum total filtration inherent plus added required for x-ray equipment producing 70 kv
2.5 mm Al
To be in compliance with radiation safety standard the fluoroscopy exposure switch must be…
Dead Man type
It is the thickness of absorber necessary to reduce radiation density to one tenth of its original value
Tenth-Value Layer (TVL)
According to the national council on radiation protection (NCRP) and measurements and regulations the leakage radiation from the x-ray tube must not be seen at ?
100 mR/hr
The primary function of filtration is to reduce?
Low energy x-ray?
The table top exposure during fluoroscopy shall not exceed to?
- 21 mGya/min (2.1 R/min) - bushong
- 2.1 mGya/min (2.1 R/min) - ppt
It is the simplify rules design to ensure safety radiation areas for occupational workers
ALARA
Give the 3 types of beam restricting device
Diaphragm, Cylinder and Collimator
The minimum thickness of the protective shielding for the bucky slot cover of fluoroscopic imaging unit should be
0.25 mm Pb
It states that the intensity of radiation at a location is inversely proportional to the square of its distance from the source of radiation.
Inverse Square Law
It produce an audible signal or temporary interacts the x-ray time
Cumulative Timer
The thickness of the absorber necessary to reduce radiation intensity to half of original value
Half-Value Layer (HVL)
A device that automatically emits the size and shape of the primary beam to the size and shape of the IR
Positive-Beam-Limiting Device
It protects the patient by limiting the area of the body and the volume of tissue is being irradiated
Collimator
It is radiation that emerged from the leaded tube housing in directions other than that of the useful beam?
Leakage Radiation
The area that can be occupied by anyone
Uncontrolled Area
Give at least 3 fluoroscopic protection
di alam; possible bucky slot cover, protective curtain
Give at least two type of monitoring personnel exposure devices
Film Badge, Thermoluminescent Dosimeter (TLD)
The intensity of the scattered radiation one meter from the patient is approximately what percent?
0.1%
Types of barrier
Primary and Secondary Barrier
It contributes to the highest occupational exposure of diagnostic x-ray personnel
Scatter Radiation
Product of the maximum mA and number of x-ray examination
Workload
what is the meaning of ALARA
As Low As Reasonably Achievable
it is use as the measurement of the penetrability
Kilovolt Peak
The maximum acceptable variation in linearity is ___ percent from one mA station to an adjacent mA station
10%
The total filtration of 50-70 kVp
1.5 mm Al
What is the total filtration operates below 50 kvp
0.5 mm Al
It measures the filtration if its unknown
Half Value Layer (HVL)
What is the total filtration for mammography in molybdenum
30 micrometer Mo
The variation in x-ray intensity should not exceed ___ percent
5%
The PBL device must be accurate to the beam ___ percent of the SID
2%
It must positively indicate when the x-ray tube energized and must indicate the condition of exposure
Control Panel
The type of exposure should be kept to a minimum
Minimize Time
Which principle is the ALARA concept primarily based on?
Minimizing the duration, distance, and shielding to reduce radiation exposure
What is the reason of minimize time in radiography
To reduce motion blur
Which safety feature is commonly found on X-ray control panels to prevent accidental overexposure?
An automatic exposure control (AEC) system
What is the primary purpose of protective X-ray tube housing?
To reduce the radiation exposure to areas outside the X-ray tube by providing shielding
What is the primary responsibility of a health physicist in a hospital setting?
Ensuring compliance with radiation safety regulations
What is an example of a practical application of the ALARA principle in a medical imaging facility?
Implementing and adhering to protocols that limit the exposure time for patients and staff
What is typically used as the material for the filtration in Xray tubes?
Copper or aluminum
What does the Half-Value Layer (HVL) measure?
The thickness of material required to reduce the radiation intensity by half
What does the effective dose measure in radiation protection?
The biological effect of radiation on the entire body, considering different sensitivities of tissues
Which unit is commonly used to measure radiation dose equivalent in health physics?
Sievert (Sv)
What is the primary function of a collimator in an X-ray system?
To shape and limit the X-ray beam to the area of interest
SSD must not less than ____cm on mobile fluoroscopes
30
RT may be in the exposure room during exposure, but only if protective apparel is worn
Operator shield
SSD must not less than __ cm on stationary fluoroscopes
38
Which of the following is the primary purpose of a lead apron in fluoroscopic procedures?
To shield the radiologic technologist from scattered radiation
What is the function of a lead shield or lead drape used during fluoroscopy?
To reduce radiation exposure to areas of the patient not being imaged
