Week 2: Radiographic Equipment

Game Plan Identify generic components of the radiographic equipment Describe various planes of x-ray tube and table movement Discuss contrast and density Exposure Factors

Generic Components of Radiographic System X-ray Tube Collimator Assembly Radiographic Table Control Console Tube support

Radiographic Room

X-ray Tube Housing

X-RAY Tube Housing Lead and steel Absorbs ______ radiation Prevents x-ray photons from leaking from tube

X-RAY Tube Made with Pyrex glass ____________ Gas Evacuated

Early X-RAY Tube

The X-RAY Tube ___________ (+) & ___________ (-) ____ and ______ housing _______ ______encased in a housing Primary components ___________ (+) & ___________ (-)

X-RAY Tube 1) 2)

X-Ray Machine Purpose: provide a specific current (mA) & voltage (kVp) to the x-ray tube _____ controls the energy of the x-ray photons _____ controls the number of x-ray photons convert electrical energy to electromagnetic energy (x- ray photons)

TO PRODUCE X-RAYS YOU NEED A SOURCE OF ELECTRONS A FORCE TO MOVE THEM QUICKLY SOMETHING TO STOP THEM SUDDENLY

Cathode Source of Electrons

Cathode Filament ________ ________ Focusing cup (beam focus)

Process of x-ray production on Cathode side (-) mA (milliamperage) is sent to filament Via cables ____________ heats up electrons “boil off” (thermionic emission) focusing cup focuses electron beam toward anode Electrons have ________ charge

A force to move them quickly. Something to stop them suddenly Anode A force to move them quickly. Something to stop them suddenly

Process of x-ray production on Anode side (+) Positive voltage (kVp) is applied Causes electrons to _________ towards anode Laws of attraction Electrons “slam into” target of anode – suddenly stopped. _________ ___________ARE CREATED

High voltage to anode attracts electrons from cathode Current to stator causes rotation of anode

Anodes - Target Rotating Anodes 2” to 5” disk (focal track) Cu W Rotation speeds Low: 3,000 – 3,600 rpm High: 9,000 – 10,000 rpm Cu Molybdenum or Graphite base W Common target (focal track)material is __________

X-ray Tube Anode Stator and rotor make up the induction motor Molybdenum stem connects rotor with anode reduces heat transfer to rotor and bearings Focal track area (spreads heat out over larger area than stationary anode configuration)

Rotating Anode Molybdenum stem and base used because it is a poor heat conductor Tungsten can withstand high heat loads

How Are X-rays Made? Source of _______move at ______ speed (KE) Collide with target or focal track on anode KE of electrons converted to x rays & heat 99% _______ 1% __________ X-rays are produced when electrons strike a metal target. The electrons are released from the heated filament and accelerated by a high voltage towards the metal target. The X-rays are produced when the electrons collide with the atoms (electrons) of the metal target

Collimator Knobs

Collimator Attaches directly below the x-ray tube Serves as a beam limiting device Controls ______ and ____ of the x-ray field

X-ray Tube: Collimation oCollimators adjust size and shape of x-ray beam oParallel-opposed lead shutters oLight field mimics x-ray field (CFR Title 21 Regs) oReduces dose to patient; ALARA: as low as reasonably achievable oLimited irradiated field → reduced scatter

Collimator Knobs

Cone collimator

Radiographic Table

Tables Tilting tables diagnostic and fluoroscopic work 90 degrees in one direction 15 – 30 degrees in the other direction ancillary equipment: footboard, shoulder support, handgrips, compression bands Tables Tilting rooms are designed for both diagnostic and fluoroscopic work Tilting models usually tilt to 90 degrees in one direction and 15 – 30 degrees in the other direction Tilting models include ancillary equipment; footboard, shoulder support, handgrips, compression bands

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TABLE OR UPRIGHT BUCKY TRAY

The ‘bucky’ is like a drawer

Image Receptors and Bucky tray Intensifying screens Film

Cassette Based 1) Film /screen (FS) 2) Computed Radiography (CR) Image Receptors Cassette Based 1) Film /screen (FS) 2) Computed Radiography (CR) Cassette-less 1)Digital Radiography (DR) Indirect Capture Direct Capture

Film Screen

Darkroom for Film Screen Image receptors

What is in the Darkroom?

Safe Light __-__ Watts _____ filter Must be __-__ feet from counter top or feed tray of processor Used to be amber or orange filter

FILM SCREEN PROCESSOR

CR- PSP plate

CR Reader for Computed Radiography image receptors

Multiloader

Digital Radiography: Direct Capture Amorphous selenium

Digital Radiography: Indirect Capture Amorphous silicon

The bucky tray can be found: In the table or chest board Holds the cassettes CR Film Screen

Bucky tray

Bucky Tray Image receptor is held in bucky

FLUOROSCOPY: Images in motion

REMOTE ROOM Conventional Room

FLUOROSCOPY must wear shielding while x-ray beam is on Lead apron Lead Curtain

Tube Supports Designed to help technologists with various tube locations for creative imaging. Tube suspension systems are available in 5 versions

Floor mounted & Overhead Suspension

Floor to Wall or Ceiling

Table Suspension Telescoping Tube

Tube Movement Longitudinal Transverse Vertical Angling or Rolling Rotating Telescoping

CONTROL CONSOLE Gives the technologist control of the xray machine Technique selection Located OUTSIDE of the Radiographic Room

kVp & mAs

The Control Console Set technical factors Make an exposure ________ Make an exposure Only a legally licensed individual is authorized to energize the console

“Technique” kVp , mAs (mA x s) What is set at the control panel How the “image” is created on the “film” or Image receptor (digital) kVp controls the “ENERGY” of the beam The Higher kVp – more penetrating Ranges is 50 -110 in Diagnostic x-ray

“Technique” kVp , mAs (mA x s) mA- is the current in combination with the time – determines HOW LONG the beam will stay on Controls the density on the film/image

Ancillary Equipment Grids View boxes and viewing computers Darkroom Processors and Readers Misc Equipment

Grids Body parts ___cm & more Lead strips parallel to centerline Absorbs _______ Improves detail

Scatter adds a _____appearance Makes image more ________

Other x-ray equipment Positioning phantoms Pixie

Other x-ray equipement Positioning sponges Lead markers

Positioning sponges

Gonad shields Lead Shields Lead wrap arounds Lead aprons

Lead Gloves and Glasses

Are x-ray machines prisoner to one room???

Mobile X-RAY equipment __________ Take machine to patient Still images Used in interventional procedures Used in surgery Dynamic images

PORTABLE UNITS

Trauma wrist done portable - using positioning devices Lead apron TAPE sponge

When patients cannot go the Radiology Department

Review

X-ray Tube Construction D F C G E

X-ray Tube Construction D. E. F. G.

TUBE HOUSING What is it made of?

TUBE HOUSING ________________

Is this rotating or stationary anode?

_______________________

What is required to produce x-rays?

What is required to produce x-rays? Requirements: ____________________________________________ ____________