Digital radiography Ch. 23 Flashcards
Digital radiography replaced film with 2 types of systems called..
CR & DR
computed radiography & digital radiography
CR uses..
a photostimulable storage phosphor imaging plate
DR has 2 types of detector configurations
direct conversion or indirect conversion
Direct conversion means …
without scintillator
Indirect conversion means…
with scintillator
What does scintillator do?
converts incoming xray photons to light
What does a photodetector do?
converts light into an electronic signal
What systems use indirect conversion?
CR and DR
In Digital radiography there can be 3 types..
cassette based CR or cassette DR or Cassette-less
In a PSP plate the 2nd layer is the..
phosphorus layer
The photo stimulable process occurs where?
inside the reader
What does ADC stand for?
Analog to Digital Converter
What can erase the PSP?
intense light
How would you loose your image on a PSP that has already been exposed?
If you leave them in the room when you are doing another exposure
What does PSP stand for?
Photostimulus Storage Phospher
Simply, what does direct capture mean?
direct conversion to electrons
Simply, what does indirect capture mean?
scintillator converts xrays into light
For direct and indirect capture how is ADC used?
the Converter changes Anode to Digital (CAD)
How long before a latent image looses 25% of its energy in a PSP?
8 hours
What does rescaling do?
compares & adjusts pixel densities
During pre processing what adjusts brightness/contrast?
the LUT
Should RTs crop or mask images that would eliminate areas of exposure from the image?
no
What does ALARA mean?
As Low As Reasonably Achievable
What are some ALARA radiation protection things we can do?
pregnancy screening, collimation, shielding
How could you become a dose creep?
By relying on windowing
How can you be a technique creep?
adjust technique apropriatly with kVp and mAs
Where is the ideal place for your EI number to be?
right in the middle of the range
