October 2014 Flashcards
Which of the following would produce the greatest dose to the patient?
A. Increased Filtration
B. Increased SID
C. Decreased SID
D. Decreased mAs
Decreased SID
Adjusting the absorbed dose value to measure biological effects of different types of ionizing radiation is accomplished by the:
Quality factor
Which of the following would NOT be used to help reduce patient dose?
A. Collimation C. Shadow shield
B. Grids D. Contact shield
Grids
The genetically significant dose (GSD) is used to assess the ______ from a source of radiation exposure.
Genetic risk to a whole population
An increase in filtration of the X-ray beam would result in an:
Increase in the half value layer
The sensing material in a thermoluminescent dosimeter badge is:
Lithium fluoride
Which of the following statements is NOT true in regard to the somatic effects of radiation?
A. Effects may occur within minutes after exposure
B. Effects may occur years after exposure
C. Somatic effects are common in radiographers
D. Somatic effects include cancer
Somatic effects are common in radiographers
In order to reduce the occupational exposure to radiation during C-arm fluoroscopy, where is the best location for the X-ray tube?
Under the patient
What is the most common type of interaction within diagnostic range of 70-150 kVp?
Compton
The rad is determined by the:
Amount of energy deposited in an absorber by radiation
Acute radiation lethality is measured quantitatively by:
LD 50/30
According to NCRP#116, the annual effective dose limits for members of the public include:
Human made radiation
The Environmental Protection Agency recommends that action be taken to reduce the level of radon in the home of the radon concentration exceeds ________ pCi/L.
4
Beam filters (collimator filters) serve to ____ in radiography.
Reduce patient exposure
Acute radiation syndrome has three separate syndromes. Which of the following is NOT one of them?
A. Central nervous system
B. Hematologic
C. Gastrointestinal
D. Cytogenetic
Cytogenetic
The radiographer’s source of radiation exposure is scatter radiation produced by:
Compton effect
Early studies of the Japanese atomic bomb survivors demonstrated a relatively high incidence of:
Leukemia
The _____ is used to determine the required thickness of a structural protective barrier.
A. Distance between the radiation source and barrier.
B. Occupancy factor
C. Workload factor
D. All of the factors above help determine the barrier thickness
D. All of the factors help determine the barrier thickness
In the diagnostic x-ray range (50-150kV) the greatest amount of absorption would occur in what?
Bone
If a patient receives ______ rad during a radiographic procedure it should be noted in the patient record, according to FDA standards.
A. 1-2
B. 10-20
C. 100-200
D. 1,000-2,000
100-200
All electromagnetic radiations possess the same:
Velocity
Only x-rays produced at the _____ shell are of sufficient energy to be used for diagnostic radiography.
K shell
Which fill factor of the pixel in a flat panel TFT digital detector will provide better spatial and contrast resolution?
A. 10% C. 50%
B. 20% D. 80%
80%
What would be the result of increasing the kVp by 20% when using automatic exposure control?
A. Increased density C. Decreased exposure time
B. Increased contrast D. Increased mAs
Decreased exposure time
The number of electrical impulses through the X-ray tube in one second that utilizes a three-phase, six-pulse system would be:
360
The output current from the secondary of the transformer is
Alternating current
The _____ uses zinc cadmium sulfide in the phosphor layer.
Image intensifier output screen
Which of the following is not produced at the x-ray target?
A. Bremsstrahlung radiation
B. Characteristic radiation
C. Compton effect
D. All occur at the x-ray target
Compton effect
The inverse square law involving distance could be applied to:
A. Intensity of radiation C. Force of magnetic fields
B. Force of electrostatic charges D. All of the above
All of the above
The material used most often for the filament is ______ because of the high melting point and because it does not vaporize easily.
Tungsten
