X-Ray Equipment Flashcards
What are the 2 types of x-ray equipment?
- Diagnostic
- Therapeutic
What are the therapeutic ranges in mA, minutes and meV (million electron-volts)?
- Less than 20 mA
- 1-60 minutes
- 4-40 meV
What are the diagnostic ranges in mA, minutes and kVp(kilovoltage peak)?
- 10-1200 mA
- 0.001 to 10 seconds
- 25-150 kVp
What are the requirements for an x-ray table?
- Supports patient
- Uniform radiolucent surface
What must the x-ray table be?
- Easy to clean
- Free of crevices that could collect contrast media
- Difficult to scratch
What does the bucky tray do?
Holds the cassette or IR
Where is the bucky tray located?
Under surface of table
What does the the bucky tray include?
Includes reciprocating grid
Cassette/grid can be _____ under patient
Cassette/grid can be MOVED under patient
What are the 2 types of x-ray table?
- Flat top
- Curved top
Describe flat top tables
- More commonly used
- Easier to judge positioning of patient for obliques
- Easier for tabletop work (extremities)
Describe curved top tables
- More comfortable for patient
- Tabletop work more difficult
- Difficult for obliques, laterals, and cross-table laterals (because patient’s body sinks down into crevice)
What are the 2 different types of table models?
Fixed (90/90) and tilting (15/90)
What are are some things that tables can have?
- Footboard
- Shoulder supports and handgrips
- Floating top
- Compression bands (also can be used for restrains)
What does the tube support hold?
Holds the X-ray tube
What does the tube support allow you to do?
Allow you to move X-ray tube with ease above the patient
What are the numerous configurations of tube supports?
- Overhead
- Floor to ceiling
- Floor
- Mobile (portable)
- C-arm
What can you use the upright unit for (types of x-rays)?
- Chest
- Abdomen
- AC joints
- Cervical spine
What are the types of portable units?
- CR capability
- Regular unit
What are other specialized diagnostic equipment (7)?
- Mammography
- Tomography
- Head units
- Dental/panoramic
- CT
- Radiation therapy simulators
- Urologic
What does the generator do?
Converts mechanical energy into electrical energy
Incoming line current are also called _____ in the U.S.
And in the U.S. we have _______ current or ___ current
Incoming line current are also called MAINS in the U.S.
And in the U.S. we have ALTERNATING current or AC current
What does a line voltage compensator do?
Measures and regulates the incoming voltage to x-ray equipment
With a line voltage compensator, if there’s any _____ in the incoming voltage, the ____ will give you a ____.
With a line voltage compensator, if there’s any FLUCTUATIONS in the incoming voltage, the METER will give you a READING.
What types of adjustment does the line voltage compensator have?
- Manual adjustment
- Automatic adjustment
Define current
Number of electrons flowing past a given point per unit of time
What can the flow of currents be?
- Direct current (DC)
- Alternating current (AC)
Define direct current
Flow of electrons in ONE direction along wire
Define alternating current
Flow of electrons going back and forth
Which one is direct current and which one is alternating current?
- Top= alternating current
- Bottom= direct current
What type of current does the US supply?
Alternating current
What type of current does the X-ray tube require?
Direct current
Define rectification
The process in which AC is changed to pulsating DC
The x-ray ____ must ____ the AC to DC between reaching X-ray tube
The x-ray CIRCUIT must CHANGE the AC to DC between reaching X-ray tube
Single-phase power is also known as…
Half wave rectification
Define single-phase power or half wave rectification
Only half of the AC is being converted into pulsating DC
What is not used in single-phase power/half wave rectification?
Opposing current
Single phase power or half wave rectification _______ the potential ______ to drop to ______ with every ______ change
Single phase power or half wave rectification PERMITS the potential DIFFERENCE to drop to ZERO with every CYCLE change
Multiphase power (“Three phase”) is also known as…
Full wave rectification
What does multiphase power or full wave rectification do?
Converts opposing half of incoming AC so electrons are always moving in same direction
Multiphase power or full wave rectification ______ ______ current so it can be ____.
Multiphase power or full wave rectification REDIRECTS OPPOSING current so it can be USED.
Which one is single phase and which one is multiphase?
Top= single phase
Bottom= multiphase
What does 1ϕ symbolize?
Single phase
What is avoided during 1ϕ?
Opposing current
What does 3ϕ symbolize?
Three phase
With 3ϕ, as each wave peak begins to _______, opposing current is ___________ (never drops to 0).
With 3ϕ, as each wave peak begins to DROP TO 0, opposing current is BOOSTED BACK TO PEAK (never drops to 0).
What percentage of kVp is recieved with a 1ϕ?
70.7% of peak voltage is used
Ex) 80 kVp selected, 56.56 kVP is what’s recieved
70.7% x 80kVp
.707 x 80= 56.56 kVp
What percentage of kVp is received with a 3ϕ, 6 pulse generator?
95.6% of selected kVP
What percentage of kVp is used in a 3ϕ, 12 pulse generator?
98.9% of selected voltage
What are the types of x-ray circuits?
- Main circuit
- Filament circuit
What does the main circuit do?
Supplies x-ray tube with current (power)
What is the purpose of the main circuit?
Produce x-rays
What does the circuit breaker control in the main switch?
Circuit breaker controls incoming power to x-ray room (on or off)
What’s an exposure switch?
2 step button - rotor on/exposure on
What does the exposure switch do?
Permits current to flow through circuit (on or off)
The exposure switch must be attached to…
The control panel
How long is the exposure switch cord on portables?
6ft
The exposure switch must be what kind of switch?
A dead man switch (automatically terminates the exposure when the finger ceases to press on the timer button)
What does the timer do?
Regulates length of time X-ray tube is connected to circuit (controls length of exposure time)
What are the types of timers?
- Synchronous timer
- Electronic timer
- Milliamperage-seconds timer (mA)
- Automatic Exposure Control (AEC)
What is the most common type of timer?
Electronic timer
How does a synchronous timer operate?
Operates from a simple motor at the same rate as the generator
How are the time values given for a synchronous timer?
In fractions - 1/4, 1/2, 3/4, 1
How does an electronic timer operate?
Operated by a microprocessor which calculates the length of time the current will flow
What is the time value for electronic timers?
Decimal time values
How does a milliamperage- seconds timer operate?
Monitors the product of mA and time.
Where are milliamperage-seconds timers (mAs) used?
Portables
What’s another term for automatic exposure control (AEC)?
Phototiming
How does an AEC timer operate?
Stops exposure time when a pre-determined density level is reached
What does an AEC or phototiming do?
Takes over exposure timer switch when a pre-determined quantity of radiation has been reached
What kind of tube does the filament circuit have?
Coolidge tube
What is a Coolidge tube and what does it do?
Coolidge tube= hot filament wire
- lengthens the life of the X-ray tube
What does the filament circuit do?
Controls the heat applied to the filament coil
What amperes and volts flow through filament coil to keep tube “warm”?
3-5 amperes and 6-12 volts flow through filament coil to keep tube “warm”
Define kVp
Potential differences in charges (anode + and cathode -) of the tube, penetration of the x-ray beam, wavelength, energy of the beam, speed of electrons, contrast or gray scale
Define ampere
Filament current (flow of electrons)
Define time
Length of exposure (time of electron flow)
What does the rotor switch do?
Turns the target
Define exposure switch
Moment of the radiation exposure
Kilo =
Kilo = 1,000
75kVp= 75,000 volts
Define volts
Unit of energy or power of the beam
Milli =
1/1000
Ex) 400mA = .4amperes
(divide by 1000 to convert)
Define ampere
Current or flow of electrons
Define seconds
Length of exposure time
What is combined to get mAs
mA and seconds are combined into one unit
mAs= mA x S
