Test 2 hailey Flashcards
In relation to x-ray tubes, what is referred to as the insert?
A)The stem of the tube
B)The point at which the anode disc is bombarded with electrons
C)The glass encasing the anode and cathode
D)The point where the power is supplied to the tube
C)The glass encasing the anode and cathode
Which of the following is NOT an advantage of a rotating anode?
A)Higher mA values possible
B)Higher kVp values possible
C)Longer exposure time possible
D)Fine focus is available at all mA values
D)Fine focus is available at all mA values
The main reason that the anode is made from a tungsten alloy rather than pure tungsten is?
A)It is cheaper to produce
B)Alloyed tungsten has less chance of cracking when repetitively heated and cooled
C)It makes the anode heavier, so it spins faster
D)It is easier to cut the radial slots in to the face of the anode
B)Alloyed tungsten has less chance of cracking when repetitively heated and cooled
When referring to the focal spot size on the anode, a focal spot of 0.6mm refers to?
A)The width of the area bombarded by electrons
B)The height of the area bombarded by electrons
C)The full of actual area bombarded by electrons
D)The area of penumbra produced on the x-ray
C)The full of actual area bombarded by electrons
Biangular anodes work with two separate filaments which are: A)Side by side B)One above the other C)Diagonal to each other D)Wound together
B)One above the other
The anode heel effect is?
A)Loss of intensity on the cathode side of the x-ray caused by the inverse square law
B)Gain of intensity on the cathode side of the x-ray caused by attenuation
C)Loss of intensity on the anode side of the x-ray caused by attenuation
D)Gain of intensity on the anode side of the x-ray caused by the inverse square law
C)Loss of intensity on the anode side of the x-ray caused by attenuation
How many rotation would a standard 3000rpm anode made in an exposure of 0.04 seconds? A)1 B)2 C)3 D)4
B)2
How many rotation would a high speed 8600rpm anode made in an exposure of 0.7 seconds? A)10 B)100 C)143 D)1003
B)100
The inverse square law is a result of what? A)Divergence B))Attenuation C)Scatter D)Absorption
A)Divergence
Using an ionisation chamber to measure the amount of radiation, an exposure al 100cm produces a reading of 76mGy. What reading would you expect if you increased the distance to 200cm? A)152 mGy B)76 mGy C)19 mGy D)8.4 mGy
C)19 mGy
Using this diagram, explain the Inverse Square Law
got to question 11 on review powerpoint xray tubes
Intensity of exposure is inversely proportional to the distance squared from the radiation.
During duelling practice, Ron is hit by a disarm charm which knocks him into a brick wall. He is taken to hospital, where on arrival he receives an AP chest x-ray taken at 95 kVp, 15 mAs, SID 180cm with a grid.
Two days later he has a follow up AP chest x-ray, but due to the limitations of the room size, it is taken at 95 kVp, SID 150cm, with a grid and x mAs.
Calculate the vale of x (to one decimal place).
Show your workings.
Answer = 0.7 x 15 = 10 mAs
Radiation Production. This is a graph of the total radiation produced by a tungsten tube after inherent and additional filtration.
What type of radiation is A
What type of radiation is B
What is the name of the given point C
look at review powerpoint xray tube question 13
What type of radiation is A Characteristic radiation What type of radiation is B Bremstrahlung What is the name of the given point C eMAX
If the cathode is heated and a potential of +35 kV was placed on it while a potential of -35 kV was placed on the anode
A)No current would flow
B)The current would flow from anode to cathode
C)The current would flow from the cathode to anode
D)No current will flow until the potential difference is greater than 40 kV?
B)The current would flow from anode to cathode
The percentage of energy that is converted into heat when the freed cathode electrons interact at the anode is approximately A)100% of total energy B)97% of total energy C)90% of total energy D)85% of total energy
B)97% of total energy
Raising the kVp A)Increases the size of the electrons B)Decreases the wavelengths in the beam C)Increases the quantity of photons reaching the anode D)Decreases quantum mottle in the image
B)Decreases the wavelengths in the beam
The mA is
A)Controlled by the temperature of the anode
B)Affected by the length of the exposure
C)Decreased threefold when a grid is used
D)Controlled by the temperature of the filament
D)Controlled by the temperature of the filament
An exposure of 80 mAs @ 70 Kvp is the same in effect as A)100 mA, 8.0 sec, @ 70 kVp B)500 mA, 0.8 sec, @ 70 kVp C)200 mA, 0.5 sec, @ 70 kVp D)400 mA, 0.2 sec, @ 70 kVp
D)400 mA, 0.2 sec, @ 70 kVp
The greater the potential difference across the cathode and anode, the
A)Greater the wavelength of the x-rays in the beam
B)Smaller the wavelength of the x-rays in the beam
C)Higher the mAs will be
D)Greater the absorption can be expected, within the patient.
B)Smaller the wavelength of the x-rays in the beam
A patient’s initial chest x-ray taken at 100 cm. The next day you are required to perform a follow up chest x-ray at 180 cm. What would be the required change to mAs needed to produce an image with similar density or brightness of the first radiograph?
A)Just under two fold
B)Exactly two fold
C)Just over three fold
D)About four fold
D)About four fold
Increasing the mAs, the MRT is
A)Making the beam more penetrating
B)Improving the quality of the beam
C)Creating more radiation
D)Creating more scatter
C)Creating more radiation
In Bremsstrahlung radiation production, the shortest wavelength is produced
A)As the photon approaches the field of the nucleus
B)When the electron is being deviated to the maximum around the nucleus
C)As the electron leaves the full effect of the nuclear field
D)As the photon is at the apex of its turn around the nucleus
B)When the electron is being deviated to the maximum around the nucleus
Half Value Layer (HVL) is defined as a thickness of attenuator that will
A)Double x-ray quantity
B)Double x-ray quality
C)Half x-ray quality
D)Half x-ray quantity
D)Half x-ray quantity
At 80 kVp, Bremsstrahlung x-rays produced in a tungsten targeted x-ray tube
A)Are all diagnostically useful
B)Are generally less useful then characteristic x-rays
C)Outnumber characteristic x-rays
D)Are less intense than if produced in a molybdenum target x-ray tube.
C)Outnumber characteristic x-rays
Characteristic radiation is produced by the
A)Incoming freed cathode electron
B)Ejected shell electron on leaving
C)Inner shell electron moving outwards
D)Outer shell electron moving inwards
D)Outer shell electron moving inwards
Ionisation is the
A)Removal of an orbital electron from an atom
B)Addition of an electron to an atoms orbit
C)Movement of an outer shell electron to an inner shell
D)Production of x-radiation
A)Removal of an orbital electron from an atom
Which statement is correct?
A)Compton scatter provides useful information on x-ray images
B)Compton scatter only occurs when low energy procedures are taking place
C)Compton electrons are unable to create more Compton events
D)Compton scatter is a source of occupational exposure
D)Compton scatter is a source of occupational exposure
When operating an x-ray system at 80 kVp:
A)None of the x-rays produced will have energy of 80 keV
B)The x-rays produced will have a minimum energy of 80 keV
C)The x-rays produced will have a maximum energy of 80 keV
D)All of the x-rays produced will have energy of 80 keV
C)The x-rays produced will have a maximum energy of 80 keV
Why does Classical / Coherent scattering have very little effecton x-ray images?
A)Only very low energy photons are affected
B)Only present in energy levels much higher than obtainable in diagnostic images
C)Classical scattering is diverted away from the IR
D)Classical scattering is not an interaction or radiation
A)Only very low energy photons are affected
Compton scatter with a scattering angle (θ) of 180° is called
A)Back scatter
B)Forwards scatter
C)Pair production
D)Photoelectric effect
A)Back scatter
How does a broad focal spot increase geometric unsharpness on a radiographic image?
A)Reduces penumbra
B)Increase penumbra
C)Increases the occurrence of scatter radiation
D)Decreases the occurrence of scatter radiation
B)Increase penumbra
In terms of radiation production, the term binding energy is defined as the energy required to
A)Remove an electron from a particular valence band or orbit
B)Bind two electrons together during interaction
C)Bind two atoms of tungsten together at the anode
D)Heat the cathode inside the x-ray tube
A)Remove an electron from a particular valence band or orbit
In this graph, which form of the following exposure factors has been manipulated?
A)kVp B)mAs C)Filtration D)SID Xray tube powerpoint question 34 for diagram
B)mAs
If a material is absorbing radiation exponentially at 10% per unit thickness, the radiation intensity would decrease in the sequence:
A)100%, 91%, 82.5%, 76%, 63.3%
B)100%, 90%, 80%, 70%, 60%
C)100%, 90%, 81%, 73%, 65%
D)100%, 81%, 64%, 49.5%, 36.7%
C)100%, 90%, 81%, 73%, 65%
In this graph, which from the following exposure factors has been manipulated?
A)kVp
B)mAs
C)Filtration
D)SID
refer to xray tube powerpoint question number 36 for diagram
A)kVp
At quidditch practice, Katie Bell has a mid air collision and is brought in for lumbar spine x-rays to rule out vertebra fractures. The appearance of the AP radiograph you produce is very white and you are unable to see cortical outline through the lumbar region. Which from the following should you do to ensure that the repeated AP image is of diagnostic quality?
A)Increase kVp by 15%
B)Double mAs
C)Increase the SID
D)Half the mAs
A)Increase kVp by 15%
A few days later, Katie presents again to the x-ray department, this time for a pelvis x-ray as she is having left hip pain when weight bearing. The exposure factors you use for your AP Pelvis are 75 kVp, 1,000 mm SID and 16 mAs. When you process the AP projection you find that there is a fair amount of quantum mottle in your radiograph and the EI is 1287. Which from the following should you do to ensure that the repeated AP image is of diagnostic quality?
A)Reduce kVp by 15%
B)Double mAs
C)Increase the SID to 1200 mm
D)Half the mAs
B)Double mAs
If the recommended manual mAs exposure for a chest radiograph on a five (5) year old child is 3.2mAs, then this can be achieved by using which from the following exposures?
A)100 mA, 0.32 seconds
B)200 mA, 0.016 seconds
C)400 mA, 0.08 seconds
D)400 mA, 0.8 seconds
B)200 mA, 0.016 seconds
In order for an x-ray tube to produce x-rays there are three essential things that MUST happen. What is NOT one of those essential three things?
A)There must be a potential difference between cathode and anode
B)The anode must be positive in respect to the cathode
C)The cathode must be emitting electrons
D)The anode must be rotating
D)The anode must be rotating
Earlier we said that 97 – 99% of the energy used in the production of x-rays is converted into heat. What is NOT a way that heat is dissipated?
A)Conduction
B)Transmission
C)Convection
D)Radiation
B)Transmission
Give two advantages and two disadvantages of rotating anodes:
ADVANTAGES
1. Can use higher kVp, mAs, time, greater thermal load
2. Faster repetition rate,
DISADANTAGES
Cost
2. Bearing wear out, less robust – mechanical stress
