Exam one 33? Flashcards
What is the last name of the person who discovered X-rays
Roentgen (Wilhelm Conrad Roentgen)
Roentgen discovered X-rays by working with the conduction of high voltage electricity through what
Vacuum tubes (Crookes tube)
What year were X-rays discovered?
1895
What are two things that X-rays do NOT have
Possess no mass and have no electrical charge
What happens to the penetrating power and frequency if you decrease wavelength
increase penetrating power and frequency
Filament is the source of electrons and it is made of what
Tungsten
What is the positively charged electrode in the tube
Anode
What part are the magnets OUTSIDE the glass envelope
Stator
What part is the shaft of copper and iron INSIDE the glass envelope, turns the target
Rotor
When the filament gains enough heat there will be boiling off of electrons from the filament, causing space charge and this is known as what
Thermionic emission
Above 70 kVp approximately 85% of the X-rays are of what origin
Bremsstrahlung
On the ANONE side what happens when the exposure button is pushed
Electrons strike the anode
The tube current is measured in what
Milliamperes (mA)
When electrons strike the target, approximately what percent of there kinetic energy is converted to HEAT while what other percent is converted to xrays
99 percent is heat and 1 percent is xrays
What determines the speed at which the electrons move in the tube current
kVp
What affects the quality and quantity of xrays
kVp
The smaller the _______ is the better the quality of the radiograph
Effective focal spot size
What is the Anode Heel Effect state
Xrays produced from the anode side of the target must go through a greater thickness of target material = a decrease in the intensity of the X-ray beam on the anode side of the tube
Federal Government guidelines require that tubes that operate above 70kVp must have a minimum of how munch aluminum equivalent total filtration
2.5mm of aluminum equivalent total filtration
The timer is a component of what side
Low voltage side
What senses changes in incoming voltages
Line compensator
What controls the tube current(current going from cathode to anode)
Milliampere selector (filament control)
What frequency type can decrease exposure time => decreasing patient dose
High frequency (chiros use this type)
What type of film screen does DR utilize
Flat panel
What is defined as the ReDUCTION in the energy of the PRIMARY beam as it passes through the body
Attenuation
What is responsible for the total absorption of the incoming X-ray photon
Photoelectric effect (deals with absorption)
Substances that contain many hydrogen atoms (water and soft tissue) have a higher what
probability Compton Scatter
Substances that contain many hydrogen atoms have a higher probability compton scatter because why
Because hydrogen has almost twice the number of electrons as most other substances
What type of person would be more likely to have compton scatter
Person with lots of water and ST (like an OBESE MALE)
The air gapping technique is used in what views
Cervical obliques
What are the 3 main components of the X-ray system
Tube, control panel, and high voltage generator
What is the weaker side between cathode and anode
Anode
Anything under 70kVp =s how much Bremsstrahlung origin
100%
