Week 1 Review

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Week 2: Radiographic Equipment 6

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 7

Generic Components of Radiographic System X-ray Tube Collimator Assembly Radiographic Table Control Console Tube support 8

9 Radiographic Room

X-ray Tube Housing 10

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

12 X-RAY Tube Made with Pyrex glass –Withstands HIGH heat loads Gas Evacuated –so electrons won’t collide with the air molecules in the tube

13 Early X-RAY Tube

14 The X-RAY Tube Lead and steel housing Pyrex glass encased in a housing Primary components ANODE (+) & CATHODE (-)

15 X-RAY Tube Most important component of the radiographic system Produces the X-rays

16 X-Ray Machine Purpose: –provide a specific current (mA) & voltage (kVp) to the x-ray tube kVp controls the energy of the x-ray photons mA 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 17

Source of Electrons

19 Cathode Filament –Thoriated tungsten Focusing cup (beam focus)

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

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

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

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

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

25 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)

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

27 How Are X-rays Made? Source of electrons move at high speed (KE) Collide with target or focal track) on anode KE of electrons converted to x rays & heat –99% heat –1% x-ray photons

Collimator Knobs 28

29 Collimator Attaches directly below the x-ray tube Serves as a beam limiting device Controls size and shape of the x-ray field

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31 Collimator Knobs

32 Cone collimator

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Radiographic Table 34

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36 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

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39 D?blend=1&ob=5#p/a/u/2/C9fTjmQrfj8

40 TABLE OR UPRIGHT BUCKY TRAY

41 The ‘bucky’ is like a drawer

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43 Image Receptors and Bucky tray Intensifying screens Film

Image Receptors Cassette Based 1) Film /screen (FS) 2) Computed Radiography (CR) Cassette-less 1)Digital Radiography (DR) Indirect Capture Direct Capture 44

Film Screen 45

46 Darkroom for Film Screen Image receptors

47 What is in the Darkroom?

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49 Safe Light 7-15 Watts Red filter Must be 3-6 feet from counter top or feed tray of processor Used to be amber or orange filter

50 FILM SCREEN PROCESSOR

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CR- PSP plate 52

53 CR Reader for Computed Radiography image receptors

Multiloader 54

Digital Radiography: Direct Capture Amorphous selenium 55

Digital Radiography: Indirect Capture Amorphous silicon 56

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

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60 Bucky tray

61 Bucky Tray Image receptor is held in bucky

62 FLUOROSCOPY: Images in motion

63 REMOTE ROOM Conventional Room

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66 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 67

68 Floor mounted & Overhead Suspension

69 Floor to Wall or Ceiling

70 Table Suspension Telescoping Tube

71 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 72

73 kVp & mAs

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75 The Control Console Set technical factors (mAs & kVp) Make an exposure Only a legally licensed individual is authorized to energize the console

76 “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 in Diagnostic x-ray

77 “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

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Ancillary Equipment Grids View boxes and viewing computers Darkroom Processors and Readers Misc Equipment 79

80 Grids Body parts 10cm & more Lead strips parallel to centerline Absorbs scatter –Improves detail

81 Scatter adds a “foggy appearance Makes image more gray

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85 Other x-ray equipment Positioning phantoms Pixie

86 Other x-ray equipement Positioning sponges Lead markers

87 Positioning sponges

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89 Lead Shields Gonad shields Lead wrap arounds Lead aprons

Lead Gloves and Glasses 90

Are x-ray machines prisoner to one room??? 91

92 Mobile X-RAY equipment Portables –Take machine to patient –Still images C-arm –Used in interventional procedures –Used in surgery –Dynamic images –Fluoroscopy

93 PORTABLE UNITS

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

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96 When patients cannot go the Radiology Department

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Review

103 X-ray Tube Construction G F E D C A B

104 X-ray Tube Construction A. Glass housing (envelope) B. Molybdenum neck of the anode C. Stators /Electromagnets D.Tungsten anode (focal spot) E. Window or port for beam exit F. Filament (cathode) G. Focusing cup

105 TUBE HOUSING What is it made of?

106 Is this rotating or stationary anode?

What is required to produce x-rays?

108 What is required to produce x-rays? Requirements: –a source of fast moving electrons –sudden stop of the electrons’ motion (KE) –kinetic energy (KE) is converted to EMS energies Heat x-ray photons