XRAY Clinicals Flashcards
Define density.
overall blackness
Define contrast.
range of densities
Define brightness.
overall lightness
Define grayscale.
rage of densities
Define contrast resolution (digital)
smallest exposure change detectable by IR
Define pixel.
picture element
Define matrix
rows & columns of pixels
Define pixel pitch/sampling pitch.
length from center of 1 pixel to center of next
Define field of view.
part of IR shown on monitor containing relevant anatomic info
Define spatial resolution (digital)
sharpness
Define sampling frequency/scan lines.
of times data is recorded as IR is read
Define exposure latitude.
range of acceptable exposures
Define image noise.
deterioration of image by signal detection interference
Define electronic noise.
noise within the system
Define quantum noise.
insufficient signal strength
Define recorded detail (analog & digital)
sharpness
Define distortion
misrepresentation of true size or shape
Define size distortion
magnification
Define shape distortion
elongation or foreshortening
Define artifact
distortion or error not related to subject studied
Define image blur
unfocused image
Define beam intensity/receptor exposure.
of xrays reaching IR
Primary factor of density
mAs
Primary factor of contrast
kVp
Primary factor of brightness
WL
Primary factor of grayscale
WW
Primary factor of contrast resolution
dynamic range & bit depth
Define bit depth
max range of pixel values computer can store (# of bits per pixel)
Define dynamic range
IR’s ability to respond to exposure
Primary components of pixels/matrix
pixel, matrix, pixel pitch/sampling pitch & FOV (field of view)
Primary factor of spatial resolution
pixel pitch/sampling pitch
What are the components of spatial resolution?
display monitor & receptor
What are the components of the display monitor in regards to spatial resolution?
pixels, matrix, FOV
What are the components of the receptor in regards to spatial resolution?
pixel pitch/sampling pitch, sampling frequency/scan lines & DELs
In CR, pixel pitch/sampling pitch is determined by what?
sampling frequency/scan lines
In DR, pixel pitch/sampling pitch is determined by what?
DEL size
How much exposure latitude does CR/DR have?
50% under/200% over
What are the components of image noise?
electronic noise, quantum noise & scatter/fog
Primary factor of recorded detail.
FSS
Foreshortening is caused by what?
angle of part
Elongation is caused by what?
angle of tube
Magnification is caused by what?
increased OID/not enough SID
Name the types of artifacts.
image receptor, processing, software, exposure
What are the types of image receptor artifacts?
cassette-based & cassette-less
What are examples of cassette based image receptor artifacts?
scratches, dust, dirt
What are examples of cassette-less based image receptor artifacts?
DEL malfunctions
What causes processing artifacts?
dirty or malfunctioning cassette processors
What causes software artifacts?
computer software issue
What causes exposure artifacts?
jewelery, clothing
Types of image blur?
receptor blur, geometric blur & motion blur
What causes receptor blur?
problem within equipment (IR, phosphor, DELs)
What causes geometric blur?
FSS, SID, OID
What causes motion blur?
motion of part, tube or IR
Another name for receptor exposure?
beam intensity
