pt 2

• what is a wet read

  stat
• when was the first automated processor made

  1942
• how long did the first automated processor take

  40 minutes
• when was the first daylight processor made

  1956
• how long did the daylight processor take in 1956

  3 minutes
• how long did the daylight processo take in 1965

  90 seconds
• how long did the daylight processor take in 1987

  45 seconds
• computed radiography (CR)

  digital processing

  filmless

  took 30 seconds
• direct radiography (DR)

  happens automatically

  could be cassette or fixed

  took about 6 seconds
• density (conventional)

  the overall degree of blackness in an image

  too dark is over exposed

  too light is under exposed

  directly related to the mAs
• density (digital)

  now called brightness

  the algorithm determines quality

  makes automatic adjustments
• brightness (digital)


  intensity of light that represents the individual pixels in the image on the monitor

  have to pick the right preset for the algorithm

  mAs does not change the brightness
• contrast (conventional)


  the difference in density between adjacent areas

  high contrast has large differences

  low contrast has lots of gray

  controlled by quality of the beam (kVp)

  high is low kVp

  low is high kVp
• contrast resolution (digital)


  difference in brightness between light and dark areas of an image
• exposure indicator (EI)


  numeric value representative of exposure IR has received

  directly proportional

  how many photons made it to the IR

  primary factor is mAs

  other factors are kVp, collimation, and the object that is exposed

  under exposed is pixely

  over exposed is too bright
• spatial resolution

  sharpness of the lines

  type of equipment can affect

  controlled by the distance between the tube, patient, and the IR
• distortion

  misrepresentation of true size and shape of object

  magnification

  shape

  affected by 3 factors

  SID

  OID

  CR
• distortion (magnification)

  if the SID is high than the magnification (beam divergence) will be low

  if the OID is high than the magnification will be high
• distortion (shape)

  if the body part is tilted in anyway

  you want the joints to be open
• motion

  will become blurry

  breathing can affect

  hard to see on tiny screen
• radiopaque

  xrays are absorbed
• radiolucent

  xrays will pass through
• lead markers

  radiopaque

  put on the specific side of the body

  AP the R will be the way

  PA the R will be flipped
• archiving

  PACS (picture archiving communication system)
• review stations

  carestream or phillips vue PACS
• portables

  allows us to bring xrays to the patients

  ICU ED or inpatient
• fluoroscopy

  created by Edison

  first commercial unit available in 1898

  live xrays
• more radiation safety regarding fluoro in 1953
• what is in a fluoro room

  fluoro table

  monitor

  xray tube

  upright bucky

  control panel

  lead lined window
• fluoro table

  can go completely standing up

  most are fixed height

  image intensifier can move up and down
• monitor


  could be mounted to the ceiling or on a stand

  mobile
• portable fluoro

  C-Arm

  xray tube is below
• xray tube alignment for table

  detent to the Bucky

  centering the IR

  choosing the SID
• xray tube alignment for screen

  SID is with the tape measure

  cannot detent
• xray tube alignment for the upright Bucky

  detent to the Bucky

  detent to the SID

  center the IR