Term
used for studies that require observation of dynamic body functions (peristallic motion)
examination of moving internal structures and fluids |
|
Definition
|
|
Term
| fluoroscopic input screen |
|
Definition
composed of sodium avtivated cesium iodide phosphors
phospors emit light photons after interacting with xrays, and turns xray beam into light
a thin protective coating is applied to prevent a chemical reaction with the photocathode |
|
|
Term
|
Definition
makes image bright
recieves the image-forming xray beam and converts it into a visible light image of high intensity |
|
|
Term
| automatic brightness control |
|
Definition
cruise control
allows operator to select an image brightness level that is maintained automatically by varying kVp, mA, and pulse time |
|
|
Term
| automatic exposure control |
|
Definition
| terminates exposure when prper radiographic density is obtained |
|
|
Term
| 3 main parts in fluoroscopic unit |
|
Definition
xray tube
table
image intensifier |
|
|
Term
| tube table distance shall be a minimum of ____ inches |
|
Definition
|
|
Term
converts an xray beam into visible light
mounted inside a metal container to prevent rough handling |
|
Definition
|
|
Term
| most image intensifiers are ____, which allows for great flexibility |
|
Definition
| multi-field (different sizes of input phosphor screen) |
|
|
Term
| Image Intensifier tube parts |
|
Definition
-input phosphor
-thin, transparent, adhesive layer
-photocathode
-electrostatic focusing lens
-anode
-output phospher |
|
|
Term
xray energy is converted to light of visible photons
coasted onto concave surface of II tube |
|
Definition
|
|
Term
bonds the input phosphor to photocathode
prevents interaction of crystals |
|
Definition
| thin transparent adhesive layer |
|
|
Term
a thin metal layer composed of cesium and antimony that takes light from input phosphor and emits electrons
xray-> light photons-> electrons |
|
Definition
|
|
Term
_____ emitted from photocathode are directly proportional to intensity of light falling on it
more remnant radiation, more light, more ____ in patient |
|
Definition
|
|
Term
negatively charged, maintains a precise path from the photocathode to the output phosphor
located along length of the image intensifier |
|
Definition
| electrostatic focusing lens |
|
|
Term
positvely charged
circular plate with aa hole in the middle thorugh which electrons pass to the output phosphor
draws negative electrons and accelerates them to output phosphor |
|
Definition
|
|
Term
| anode is supplied with about ___kV |
|
Definition
|
|
Term
makes image brighter
site where electrons interact and produce light
made of zinc cadmium sulfide crystals and plated with a thin layer of aluminum |
|
Definition
|
|
Term
| each photoelectron that arrives at the output phosphor results in ___ to ___ times as many light photons as were necessary to create it |
|
Definition
|
|
Term
| ratio of the number of light photons at the output phosphor to the number of xrays at the input phosphor |
|
Definition
|
|
Term
|
Definition
| FG= output light/ input xrays |
|
|
Term
| the ratio of the square of the diameter of the input phosphor to the square of the diameter of th output phosphor |
|
Definition
|
|
Term
|
Definition
|
|
Term
| the product of minification gain and the ratio of the number of light photons at the output phosphor to the input phosphor |
|
Definition
|
|
Term
|
Definition
|
|
Term
| a measure of the speed of the screen |
|
Definition
|
|
Term
| ratio of number of light photons at the output phosphor to the number of xrays at the input phosphor |
|
Definition
|
|
Term
|
Definition
| = #of output light photons/ #input xray photons |
|
|
Term
|
Definition
| measures efficiency of intensifying screens |
|
|
Term
provide greater flexibility in all fluoroscopic examinations
zoom in/ out |
|
Definition
|
|
Term
|
Definition
better spatial resolution
better contrast resolution
higher patient dose |
|
|
Term
also known as "white noise"
measured as the signal to noise ratio
increased noise has an inverse relationship to contrast |
|
Definition
|
|
Term
| ability of imaging systems to accurately disply objects in a two dimensional format |
|
Definition
|
|
Term
| image intensifiers are capable of increasing image brightness _____times |
|
Definition
|
|
