Docstoc

RADIOGRAPHIC EQUIPMENT_W1_11

Document Sample
RADIOGRAPHIC EQUIPMENT_W1_11 Powered By Docstoc
					RADIOGRAPHIC
 EQUIPMENT

Adler & Carlton Ch. 8
         &
   Bushong Ch. 1
Modern radiology
   Two basic types of x-ray examinations

    • Radiography
    • Fluoroscopy


                                       2
Radiography exam




                   3
Radiographic Room
The transformation from a physicist toy to a
  valuable, large scale medical specialty
• 1907 Snook transformer – high voltage

• 1913 Coolidge x-ray tube – air evacuated,
 separate selection of voltage and current


• Standardizing x-ray tube beam output



                                               6
          THE X-RAY TUBE



• The X-Ray tube is
  the single most
  important component
  of the radiographic
  system. It is the part
  that produces the x-
  rays
        THE X-RAY TUBE
• GLASS ENCASED IN
  STURDY STEEL
  HOUSING
• PRIMARY
  COMPONENTS
  – ANODE +
  – CATHODE --
    XRAY TUBE HOUSING
• MADE OF LEAD AND STEEL

• TO ABOSRB ANY STRAY RADIATION

• TO PREVENT LEAKAGE RADIATION
  FROM THE TUBE
   TUBE HOUSING
MADE OF LEAD & STEEL
    How “X-rays” are created
      SEE:   MAN MADE RADIATION (PG.111)
                 Adler & Carlton

      TO PRODUCE X-RAYS
          YOU NEED:

• A SOUCE OF ELECTONS
• A FORCE TO MOVE THEM QUICKLY
• SOMETHING TO STOP THEM SUDDENLY
     How “X-rays” are created
• Power is sent to x-ray tube via cables

• mA (milliamperage) is sent to filament on
  cathode side.

• Filament heats up – electrons “boil off”

• Negative charge
    How “X-rays” are created
• Positive voltage is applied to ANODE
• Negative electons = attracted across the
  tube to the positive ANODE.

• Electrons “slam into” anode – suddenly
  stopped.

• X-RAY PHOTONS ARE CREATED
     How “X-rays” are created
• Electron beam is focused from the cathode
  to the anode target by the focusing cup

• Electrons interact with the electrons on the
  tungsten atoms of target material

• PHOTONS sent through the window PORT –
  towards the patient
More on the tube later……..
X-RAY TABLE
Radiographic tables
   Are designed to support the patient
    during a radiographic exam
   Comfort is not the primary concern
   Foam pads should be used if the patient
    will be required to be on the table for
    longer than 10 minutes
Tabletop
   Must be uniformly radiolucent to easily
    permit x-ray to pass through.
   Carbon fiber is used because it is strong
    and very little x-ray photons are
    absorbed.
   Usually tabletops are flat however some
    are curved
Tabletop
   Most tabletops are floating, some are
    motor-driven
   The brakes can be released usually by
    the technologist hand or foot
   The brakes are electromagnetic
   Floating table tops save significant
    amounts of time and strain on the
    technologist
Tables
   Tables are fixed or tilting
   Fixed rooms are designed for diagnostic
    radiographic work only
    • The table can usually be raised or lowered
      to accommodate the patient and
        the technologist.
Table top technique
   Performing
    imaging using
    just the cassette,
    plate or digital
    image receptor
   Also called “non-
    grid” technique
Fluoroscopy exam




                   26
FLUOROSCOPY
IMAGES IN MOTION
Fluoroscope
 1898 by Thomas Edison




                          28
     Radiation Injury
      1904 the first recorded x-ray fatality in the US – Clarence
       Dally, Edison’s assistant
      Early injuries took the form of skin damage, loss of hair and
       anemia
      Snook transformer & Coolidge tube reduced the injuries
       Why?




29
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
             Table
         Movement
   Longitudinal
   Transverse
   Vertical
   Tilt or Angling
Fluoroscopy tables: the tube is under the
table, image capture is above the patient
Tube Supports
   Designed to help technologists with
    various tube locations for creative
    imaging.
   Tube suspension systems are available
    in 5 versions:
    • ceiling mounted, floor-to-ceiling, floor, mobile
      and c-arm.
              Tube
          Movement
•   Longitudinal
•   Transverse
•   Vertical
•   Angling or Rolling
•   Rotating
•   Telescoping
Improvement in radiography
   Reducing exposure time to reduce blur

   Dentist William Rollins began using a
    diaphragm to improve image quality
    • First application of collimation and filtration

   1921 Potter-Bucky grid – improving image
    contrast


                                                  42
Dr. William Rollins
       • Dr. William Rollins was a
         Boston physician and
         dentist who was the first to
         use collimation and filtration
         in the late 1800s.
       • After receiving radiation
         burns to his hand in x-ray
         experiments in 1898, he
         used leather and aluminum
         filters when he made x-ray
         exposures of his patients'
         teeth.
                                    43
             The ‘BUCKY’
• The Potter-Bucky is
  the device in the
  table or chest board
  that holds the film
  cassette. The
  „bucky‟ is like a
  drawer that opens
  and closes to insert
  and remove the film
  cassette.
TABLE OR UPRIGHT
   BUCKY TRAY
Radiographic
       grid ?
         Bucky cross hatched
• Grids are used to
  “clean up” scatter
  radiation from the
  patient
• To improve
• contrast on the
  radiograph
• Potter-Bucky are
  usually a focused
  moving grid
CASSETTES W/ GRID CAPS
Radiation shields
           Viewing
           images
• View boxes

• Computer monitors
          COLLIMATOR
• ATTACHES
  DIRECTLY BELOW
  THE X-RAY TUBE
• SERVES AS A X-
  RAY BEAM LIMITING
  DEVISE
• CONTROLS THE
  SIZE AND SHAPE
  OF X-RAY FIELD
Cone collimator
• ALWAYS
  KEEP THE
  COLLIMATED
  AREA
  SMALLER
  THAN THE
  SIZE OF THE
  CASSETTE
                 X-ray tube
                  controls
• Displays
  – Tube angle
  – Distance to table top
    bucky
  – Collimator controls
  – Tube lock controls
  – High voltage cables
   CASSETTE or FILM HOLDER
• The CASSETTE is
  used to hold the film
  during examinations.
  It consist of front and
  back intensifying
  screens, and has a
  lead (Pb) backing.
  The cassette is light
  tight
• CR image capture

• PSP Plate

• PHOTOSTIMULABLE
  PHOSPHOR PLATE
                  FILM
direct exposure & screen-film or film-screen
                            SIZES
                              14 X 17
                              14 X 14
                              11 X 14
                              10 X 12
                              8 X 10
             Film Sizes
Standard “inches”:   Metric:
 8” x 10”             18cm x 24cm
 10” x 12”            24cm x 30cm
 11” x 14”            30cm x 35cm
 14” x 17”            35cm x 43cm
• DR(DDR)

• Collection element
• TFT (Thin film
  transistor)
• Photodiode
• CCD (charge-coupled
  device)
      CONTROL CONSOLE
• GIVES THE
  TECHNOLOGIST
  CONTROL OF THE
  X-RAY MACHINE

• TECHNIQUE
  SELECTION
• Located OUTSIDE of
  the Radiographic
  Room
      The Control Console
• The control console is
  device that allows the
  technologist to set
  technical factors (mAs
  & kVp) and to 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
     + 30%
+ 50 % mas
kVp Changes
Darkroom
What is in the Darkroom?
               Safe Light
• 15 Watts
• Red filter
• Must be 3-6 feet
  from counter top or
  feed tray of
  processor
• Used to be amber
  or orange filter
UNLOAD EXPOSED FILM
FILM ID PRINTER
FILM BIN - STORAGE
 Transport System (Rollers)
        Entrance   Crossover
Feed Tray
                               Squeegee


   Deep
   Racks                         Dryer

   Turnaround
 Analog
processor
                CR
          processor
• What does a DDR
  processor look like?
         Other x-ray stuff….
• Positioning phantoms
• Pixie
Dosimeter
   An instrument that detects and
    measures exposures to ionizing radiation
   Personal vs Field survey instruments
Densitometer
   Measures optical density on a
    radiograph
Step wedge or penetrometer
   Test tool made from aluminum
   Accurately-calibrated filter strip that
    provides a stepped range of exposures
           Other x-ray stuff….
• Positioning sponges

• Lead markers

• Gurney

				
DOCUMENT INFO
Categories:
Tags:
Stats:
views:4
posted:1/16/2012
language:
pages:90