Este Quiz é cronometrado.
Você tem 1 hora 20 minutos para completar as 122 questões deste quiz..
The distance between two consecutive corresponding points on a wave is?
Frequency
Cycles
Wave
Wavelength
X-rays are?
Visible with ultraviolet light
Visible while in the dark room
Only visible when it is being shot
They are like JOHN CENA and you cant see them
The higher that the frequency of x-ray waves are...
The higher the penetration
The lower the penetration
Wave length is?
Variable
Does not change since it goes in only a straight line
X-ray penetration depends on atomic number, x-ray energy, and density
Waves that are longer have___?
Lower frequency
Higher frequency
The lower the frequency the _____ the penetration power
Lower
Higher
The cathode is?
Negative
Positive
The anode is?
Which consists of the wire filament and focusing cup?
Anode
Cathode
90% heat and 9% X-rays
99% heat and 1% X-rays
1% heat and 99% X-rays
50% heat and 50% X-rays
What provides and houses the vacuum environment?
Glass envelope
Focusing cup
Wire filament
Aluminum filter
Produces electrons when heated
What is the wire filament made of and why?
Tungsten; high atomic number and high melting point
Molybdenum; low atomic number and high melting point
Copper; high atomic number and low melting point necessary for electron production
Aluminum; high atomic number, high melting point
mA is?
How many electrons
Speed of the electrons
kVp is?
Speed of electrons
The higher that an atomic number is....
The more dense it is
The less dense it is
If x-ray beams went all the way to the film..
You would see black
You would see white
If you see white on the finished radiograph, this tells you?
The x-ray beams were absorbed
The x-rays beams penetrated and reached the film
What is the wire filament heated by?
Low energy circuit
High energy circuit
X-rays beams can cause cataracts in humans
Objects that fluoresce or emit light after an x-ray has been shot indicates that the x -ray machine wire filament is faulty
The focusing cup is made of what material and why?
Molybdenum; high melting point and poor conductor of heat
Tungsten; high melting point and great conductor of heat
The target of the anode is made of what material and why?
Tungsten; dissipates heat
Molybdenum; high melting point
What would tell you that heat damage have occurred in a dental anode?
Cathode will not make a cloud of electrons
Finished radiograph is too light
There will be no radiograph made
You will hear a loud machinery noise inside of the anode side
The heel effect is more prominent in?
Rotating anodes
Stationary anodes
What is the heel effect?
causes increased absorption of x-ray photons by target before can reach patient due to decreased intensity at anode side
causes increased absorption of x-ray electrons by the cathode
Results in crazing which is when glass pieces fall and can "arch" the current
Results in decreased absorption of quanta at the target before can reach patient and image receptor due to increased intensity on cathode side
The most common focal spot in a veterinary machine is?
2mm squared
3mm squared
7-8mm squared
10mm squared
In regards to x-ray, pneumbra is?
1996 band formed in France and wrote the song "Tragical Memories"
Lighter than normal x-ray phenomon
Larger focal spots that form halo effect on finished radiograph
Darker than normal x-ray phenomon
During the heel effect, there is?
Decreased intensity at anode side
Decrease intensity at cathode side
Increased intensity at cathode side
Increased intensity at anode side
In most situations, larger focal spots produce images with?
Greater detail
Reduction of detail
The ____ the anode, the more severe that the heel effect becomes
faster
slower
larger
steeper
Which would have the larger focal spot to dissipate heat?
Rotating anode
Is a tightly focused x-ray beam that exits the tube window
Effective focal spot
Focal spot
Line focus principle
Anode beam
Which is larger?
Actual focal spot
In an x-ray, the dog's head is usually towards the?
Outer edges of focal spot become so hot that the size of the focal spot is enlarged, a phenomenon referred to as?
Focal spot bloom
Heel effect
Net result of focal spot bloom is?
Increase in quality
Loss in sharpness
Loss in sharpness and definition
increase in sharpness
Most tube failures happen because of?
Cathode failure
Anode failure
Filament failure
Focusing cup failure
The x-ray does not have to cool between x-rays
Which is not true of the standby current?
Prolongs life of the tube
Produces an electron cloud prior to an actual x-ray (good for inhalation and exhalation)
Preheats filament to a low temperature when X-ray machine is turned on
You are going to take an x-ray of the abdomen with the use of the preexposure button. You are waiting until?
Expiration
Inspiration
You are going to take an x-ray of the thorax with the use of the preexposure button. You are waiting until?
If the film is transparent or light after processing, there is most likely an issue with the?
Filament
Preexposure button
Firm blackness that is not uniform could be due to?
Anode target failure
Anode bearings failure
Glass envelop damage
Which is most likely to fail with the use of preexposure button over an extended period of time?
Anode bearings
Anode target
The mAs meter on the machine is stuck. You suspect?
Preexposure button failure
You should use ___ mAs techniques when possible
high
low
What may cause arcing?
Effective focal spot bloom
Provides the electrical potential to drive the electron cloud in stream from cathode to anode
high voltage circuit
Low voltage circuit
Provides electricity to heat the filament
High voltage circuit
Reduces voltage of incoming line to about 10 volts
Autotransformer
Step-up transformer
Step-down transformer
Biotransformer
In general, what part of the x-ray dissipates heat for the entire machine?
Oil
Controls amount of kVP across the x-ray tube
Which circuit is connected to the mA control on the console
You want to keep exposure times of 1/30 second or longer
Which is used for portable units
Half wave rectification
Full wave rectification
If you want to decrease potential of x-ray exposure to the technician, use a timer switch
Which only uses the positive part of the electrical current in regards to half way rectification?
Dental units
Stationary units
Why are rectifiers used?
When anode gets too hot, electrons can flow back to filament and damage it
When cathode gets too hot, electrons can cause damage to the glass envelope
"crazing" and "arcing" can both occur
X-rays that are constantly used can result in anode bearing damage which results in lighter x-rays
What does a colimator do?
Controls size of x-ray
Controls heat of x-ray
Controls strength of x-ray
Helps prevent focal spot blooming
Scatter radiation is a negative result of an uncontrolled beam that can result in?
Cathode damage and failure
Anode bearing failure
Oil leakage and overheating
Fogs the film
Coning down prevents?
Damage to the cathode
Damage to personnel
Damage to the filament
Overheating
You are working in California and the X-ray machine you are using has an output of 75 kVp. The state law in California says that you are required to have which of the following on your x-ray machine?
2.5mm aluminum filter
Collimator (AKA: Coning down)
What is the #1 cause of artifacts on a radiograph?
Motion
Glass window cracking (crazing and arcing)
What does the control panel not include?
Warning light
kVp and mA selector
voltage compensator
Exposure button
Timer
Emergency turn off switch
Which is not a factor of X-ray tube rating?
Focal spot size
Target angle
Anode speed
Electrical current
Alloy composition
What do X-ray tube ratings determine?
kVP
mA
How long can be used without overloading the tube
All of the above
What adjusts the transformer if needed when electrical output from incoming line is inconsistent?
Rectification
Voltage compensator
Colimator
A three phase generator is more powerful than a single phase generator because there is an almost always constant current between anode and cathode since it superimposes three single phase currents out of phase with each other
The mA cannot be controlled when air molecules interfere with the electron flow following glass envelope damage because there is less x-rays produced at the target area
The negatively charged particle of an atom is?
Electron
Proton
A radiograph is synonymous with an x-ray
True
False
Frequency is measured how?
Cycles of the wave that pass stationary point per second
Cycles of the wave that pass stationary point per minute
Cycles of the wave that pass stationary point per hour
Atoms consist of?
Particles
Electrons
Neutrons
X-ray machine rays can bend and turn corners as needed which is why safety glasses are required
The actual beam from a machine is called?
X-ray
Radiograph
X-rays can excite or ionize atoms which can be a source of tumors and tissue damage if precautions are not taken
The guy that discovered x-rays and documented them in 1895 is:
Which of the following do we need to produce an x-ray
Source of electrons
Way to accelerate electrons from one side of the tube to the other
Vacuum environment to remove air molecules and prevent oxidation
Target for electrons to collide with and interact with to produce x-rays
A mammography machine is likely to be made of?
Tungsten
Molybdenum
Why is the base of the anode copper?
Draws heat away from target
Used to help make electrons and shoot them forward
Prevent scatter radiation as a result of stray electrons on their way from the cathode side
All of the above are true
Which of the following anodes will rotate on its axis through the center of the tube
Stationary anode
Portable anode
Dental anode
Disk shaped anode
Portable units and dental units both rotate on their axis
What is the red arrow pointing to?
What is the red arrow?
Window
Filter
Both Filament and focusing cup
The red arrow is pointing towards?
Target
Cathode filament and focusing cup
Radiation is emitted from the target area in a ___ shape with the heel effect
Conical
Square
Which is the most limited in mA and has limited use on large body parts?
Portable anodes
Disk shaped anodes
How do you get mAs?
mA x time
mA x kVp
mA x time divided by kVp
Waves from high frequency generators are usually?
Circular
Watery with lots of air require?
Higher mA
Lower mA
Which is a normal mA setting?
100
44
Which is a normal Kvp setting?
46
200
The primary purpose of the x-ray tube is to stop stray radiation AND prevent damage to internal components
Do shorter or longer wave lengths have better penetration?
Shorter
Longer
Bundles of energy that are carried by the wave in an x-ray beam are called?
Photons
Quanta
Both Quanta and Photons
Specific target angle that produces effective focal spot that will be square and much smaller than the actual focal spot
Focal spot zoom
Which produces more heat?
500 mA
300 mA
The kilovoltage applied between the anode and cathode will later translate into penetrating power
If anode bearings fail completely in a machine, you will hear a loud noise almost like a machinery noise from the anode side when attempting to use the exposure or pre-exposure button
Aluminum filters help to?
Remove low energy photons
Remove high energy photons
Remove high energy electrons
Remove low energy electrons
If the warning light turns on during the x-ray exposure, this indicates an issue with the machine and requires immediate technical support
Which has more filaments
Portable machines
Floor models
The heel effect is the result of?
X-ray emission that is nearly parallel to the target itself
X-ray emission that is nowhere near the target but is actually arced away
X-ray emission that is nearly perpendicular to the target itself
What kind of anode would you choose to decrease the heel effect?
25 degrees angled anode
15 degrees angled anode
18 degrees angled anode
To withstand heat from electron bombardment, focal spot has to be larger than what is perfect for great detail so you find a medium between detail and size
IS the rotating anode, the filament is angled to direct electrons toward the beveled target area of the rotating disk to distribute heat
In stationary anodes, the face of the target is angled toward the window and cannot withstand high heats
true
false
Which will better absorb photons
More dense
Less dense
Rotating anodes can have smaller focal spots than stationary anodes
Anode bearing failure is most often seen in?
The majority of tube failure is user error
Rectifiers are placed in series in high voltage part of circuit to prevent conduction during negative phase
High-frequency generators often have hills and valleys
Full wave rectification current pulses 120 times/second and is twice the x-ray production and decreased exposure times
Which does not use tungsten?
The spindle which dissipates heat for the rotating anode is made up?
Which is a poor conductor of heat?
Which is better at dissipating heat?
If the anode bearings are just starting to go bad, you will hear a machinery like noise and target will overheat