Ch.20 Flashcards
Two types of digital radiography systems
CR and DR
This type of digital radiography deals with photostimuable imaging plates (PSP, IP)
CR
Referred to as flat panel detectors (panels)
DR receptors
This type of digital radiography deals with direct conversion without scintillator and indirect conversion with scintillator
DR
What type of digital radiography system does healthcare reimbursements encourage?
DR
When were the most changes made as far as historical development?
1970s and 1990s
-digital computerization of CT, ultrasound, MRI, Mammo
Requires binary machine language
two symbol alphabet
(0 and 1)
Bit versus byte
8 bits=1 byte
Digital image formation must be converted to digital language
Analog-to- digital conversion
ADC involves two distinct steps
Sampling and qualification
Computer memory and power expressed in total bytes
-megabytes, gigabytes, terabyes
Digital data consists of bit values
Binary digit
Bit strings connected as:
Bytes
made up of pixels and voxels
-field of view (FOV)
-spacial resolution dependent on matrix size
matrix
pixel
picture element
voxel
volume element
is a matrix of picture elements (pixels)
Digital image
An arrangement of cells in rows and columns
-each cell corresponds to a specific locations in the image
Matrix
Holds image in plate
PSP
-holding latent image
latent image
not able to see image
manifest
able to see image
PSP
photo simulator phosphor
what is now applied to all imaging modalities
-visualization of anatomy in multiple planes
-computer manipulation of imaging data through sophisticated post-processing software
-adjusting to image
-pre-processing
-built in
-corrects grays
-can enhance pathologies
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