Transcript X-ray tube - El Camino College

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THE X-RAY TUBE
Electromagnetic Energy Spectrum
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THE X-RAY TUBE
Electromagnetic
Radiation
Bits of energy
that passes thru
matter
Travels at the
speed of light
Not always
ionizing!!!!
photon
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THE X-RAY TUBE
REVIEW OF X-RAY DISCOVERY
CROOKE’S TUBE
WILHELM ROENTGEN’S OBSERVATIONS
November 8, 1895
BERTHA ROENTGEN’S HAND
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THE X-RAY TUBE
What do you need to
produce ionizing
radiation?
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THE X-RAY TUBE
A source of electrons
A force to move them quickly
Something to stop them very
suddenly
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THE X-RAY TUBE
Remember the light bulb!!
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The source of electrons
THE X-RAY TUBE
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THE X-RAY TUBE
The Law of
Attraction
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THE X-RAY TUBE
Simple car battery
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THE X-RAY TUBE
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Let’s make
This terminal
Very positive
Let’s make this
terminal very negative
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THE X-RAY TUBE
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THE X-RAY TUBE
anode
cathode
X-ray
tube
Glass
envelope
Tube
housing
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THE X-RAY TUBE
Focusing
cup
cathode
Tungsten
filament
Milli
ampereage
Thermionic
emission
Electron
cloud
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THE X-RAY TUBE
target
anode
High
voltage
tungsten
Rotating
Focal
track
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THE X-RAY TUBE
Cathode
Anode
filament
Target/focal track
Focusing cup
rotor
Milliamps
kilovolts
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THE X-RAY TUBE
CATHODE
ANODE
VACUUM
GLASS ENVELOPE
CURRENT
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THE X-RAY TUBE
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THE X-RAY TUBE
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THE X-RAY TUBE
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THE X-RAY TUBE
anode
cathode
X-ray
tube
Glass
envelope
Tube
housing
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THE X-RAY TUBE
Glass Envelope Tube Housing
vacuum
Lead and steel
Pyrex glass
Surrounds anode and
cathode
Port for exit beam
Surrounds glass
envelope
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THE X-RAY TUBE
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THE X-RAY TUBE
anode
cathode
Glass envelope
Lead casing
oil
Port/window
steel casing
Which end of tube is the positive end?
Which end is the negative end?
Is this a stationery or rotating anode?
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THE X-RAY TUBE
What is electromagnetic spectrum?
What are photons?
What is radiation?
What is ionizing radiation?
What is x-ray?
What are roentgen rays
What are photons?
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THE X-RAY TUBE
TThe amount
of time
charged is
applied
The amount
of electrons
burned off
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THE X-RAY TUBE
The amount of
electrons burned off
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Milli-amperage
Electron cloud
Thermionic Emission
Focusing cup
??amount of
electrons???
• ? How many mA are
applied?
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THE X-RAY TUBE
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The longer the the
milli-amps are applied,
the more electrons are
burned off.
The amount of time
charged is applied
• How many seconds are
• applied?
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THE X-RAY TUBE
The stronger the force of the
positive charge, the faster the
electrons rush toward anode,
The more x-rays are
generated.
The force of the charge is
measured by kilovoltage (kV)
applied to the anode
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THE X-RAY TUBE
milli-Amperage (mA)
Time-(in fractions of
seconds)
kilo-Voltage (kV)(kVp)
technique
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CONTROL PANEL
Where the technologist controls the x-ray
machine
Where technique selection occurs
Always located outside the x-ray room
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CONTROL PANEL
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CONTR0L PANEL
 kVp controls Strength of beam
 kVp
more penetrating
 50-110 kVp in diagnostic x-ray
 Controls contrast and density on
 image
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CONTROL PANEL
 mA controls the amount of
electrons
 Time controls how long the
electrons are sent to anode
 Frequently used as a single unit
of measure
mAs
 Controls the density of the image
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ANCILLARY EQUIPMENT
 Image Receptors
 Table
 Tube supports
 Grids
 Collimators
 Misc Equipment
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IMAGE RECEPTORS
Film cassettes
CR cassettes
Direct imaging
Bucky tray(grid)
Wall Bucky tray(grid)
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IMAGE RECEPTORS
Film Cassettes are light tight, with intensifying screens. They serve to
hold the film safe from any damage. CR cassettes look almost identical but
contain a PSP plate that is used to create the image.
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IMAGE RECEPTORS
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TABLE
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TABLE
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TABLE
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TUBE SUPPORTS
Tube Suspension systems are available in 5
versions. Be sure to check the book for
configurations.
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TUBE SUPPORTS
Designed to help technologists with
various tube locations for creative
imaging.
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TUBE SUPPORTS
Tube Movement
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Longitudinal
Transverse
Vertical
Angling or Rolling
Rotating
Telescoping
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COLLIMATORS
Limits the X-ray field
Limits the transverse
and longitudinal field
Positive beam
limitation
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COLLIMATORS
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COLLIMATORS
Always
collimate
smaller than
the image
receptor
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GRIDS
Device used to “clean up” the
x-ray image by reducing the amount of
scatter radiation reaching the image
receptor
Used on larger, thicker parts
Built with parallel lead strips to absorb
the scatter radiation
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GRIDS
???
+
-
Primary beam
Exit Radiation
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GRIDS
No grid
grid
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GRIDS
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MISCELLANEOUS EQUIPMENT
Positioning sponges
Tape
Lead aprons
Lead blockers
Markers
Sand bags
linens
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MISCELLANEOUS EQUIPMENT
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MISCELLANEOUS EQUIPMENT
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PROCESSING ROOM
 Film Screen Image
Production
 Digital Image
Production
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PROCESSING ROOM-IMAGE PRODUCTION
???
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Primary beam
Exit Radiation
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PROCESSING ROOM-IMAGE PRODUCTION
RADIOGRAPH- PERMANENT RECORD OF IMAGE, BY FILM
OR BY COMPUTER STORAGE
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DARK ROOM
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DARK ROOM
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DARK ROOM
 Pass Box
 Lockable from inside, contains cassettes
 Clean, dry, dustless countertop
 Work space be free of clutter
 Safe light
 15 watt bulb
 3 feet from film, countertop
 Orange or amber filter/light bulb, depends
on film emulsion type
 Cassettes, empty and full
 Film bin
 Must be light tight
 Sometimes locks with door
 Processor
 Needs water supply,
 Must be clean
 Chemicals
 Store safely
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DARK ROOM
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DARK ROOM
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CR READER
CR - Computed Radiography
Computed Radiography is an indirect type of imaging system. The receptor
used within a CR cassette is called a photostimulable imaging plate (PSP) and it
absorbs the radiation exiting the patient. The exposed plate is processed in a CR
reader, where the absorbed energy is extracted. The information stored in the CR
imaging plate must be processed before viewing can occur. The resultant latent
image data is converted from an analog to a digital signal and a digital image is
created. Computed Radiography x-ray systems predominantly use conventional xray tube systems.
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CR READER
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REVIEW
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REVIEW
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REVIEW
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REVIEW
A source of electrons
A force to move them quickly
Something to stop them very
suddenly
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THE X-RAY TUBE
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8. Describe
tube travel
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7. Describe
Tube Travel
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9. Describe how the tube would travel in order to direct xray output at #1??
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