IP
what happens to fluoroscopic images of thicker body parts, if other factors stay constant?
the image becomes dimmer
what happens when switching from a larger to a smaller input phosphor size?
electron focal point moves farther from output phosphor, which reduces the field of view and magnifies the image.
A fixed fluoroscopy unit is _______?
stationary
what is the formula to calculate bit depth?
1. 2n
2. n is the number of bits, could be 10, 12, 14, or 16
3. 2 is the number of bit values 2= 0 or 1
what is the purpose of the protective layer?
to protect the phosphor layer
How is fluoroscopic mA related to image brightness?
directly related. higher mA=brighter images.
in Mag mode, how does the electron focal point move?
moves closer to the input phosphor
a mobile fluoroscopy unit is a ________?
C-arm
what is the total number of bit value?
2
what is the purpose of the phosphor layer?
active layer containing photostimulable phosphors (usually barium fluorohalide crystals) that trap electrons during X-ray exposure to form a latent image.
what determines magnification mode in fluoroscopy?
input phosphor size
what happens to patient dose in Mag Mode?
patient dose increases.
what is a bit?
singe unit of data. smallest unit of data with values of 0 or 1
What is:
cassette based equipment, uses a lightweight, individually identified cassette that contains an imaging plate with a photostimulable phosphor as the IR.
computed radiography (CR)
what is the purpose of the reflective layer?
Directs emitted light toward the photodetector (reader) to increase signal efficiency
How is magnification mode achieved in fluoroscopy?
by reducing the size of the input phosphor area focused on the output phosphor screen.
what happens to image quality in mag mode?
better spatial and contrast resolution.
what is a byte?
grouping of Bits, 1 Byte= 8 bits
what imaging plate is used in CR?
PSP plate
what is the purpose of the conductive layer?
A layer that reduces electrostatic charge (anti-static) and improves spatial resolution by absorbing light.
What is:
image is electronically enlarged by using a smaller input phosphor area?
Mag mode
As the distance between image intensifier and your fixed source of radiation decreases, patient dose will________?
patient dose decreases.
what does bit depth determine?
the number of gray shades per pixel (grayscale)
what is the main layer of a CR imaging plate?
phosphor layer
what is the purpose of the support layer?
A semi-rigid base that provides mechanical strength to the imaging plate.