who invented the flouoroscope in1896
thomas edison

<question>
regular xray is _____
floro xray is _____
</question>
static 
dynamic

<question>
what is the lowest portion of the body that the tube can be from the patient when using floro 
what is this distance called
</question>
15cmm
source to skin distance  

what are the two light receptors of the eye
rods and cones

what is photopic vision
when the cones of the eyes require bright light or daylight

scotopic vision
when rod vision is used in dim light or complete darkeness (like in darkroom of the xray to process films)

what is the best position of the body for fluid to dump into the small intestine
RAO

what is the primary function of fluoroscopy
is to perform dynamic studies to visualizethe motion of internal structures and fluids

what permits the IR to be reaised and lowered to vary the ofd and gain maximum resolution while the tube remains in position
C arm it permits scanning the length and width of the table

<question>
what is a carriage 
what structures does it include
</question>
the arm that supports the equipment suspended over the table 
image intensifier, control for power to drive the carriage, spot film selection, tube shutters (collimation), on/off dead man switch, height lock

where is the xray tube in a floro unit
in the table

<question>
what is the floroscopic range mA range
how much is the typical diagnostic range for an xray tube 
why is range so low
</question>
0.5-5.0 mA
25-1200 mA
because floro tubes must operate for long periods of time

a fixed SOD of ____ is used to prevent any closer movemtn of tube
15 in

what is the purpose of image intensification tubes (2 reasons)
designed to amplify the brightness of an image
reduce patient dose while maintaining image qualtiy  

anything with the word screen or cathode means what
screen = means it produces light 
cathode means it produces electrons

what general technical fasters are used to increase brightness in fluoro
high kvp low mA

<question>
what is the first layer of the II (image intensifier)
what is this layer made out of and what is the function
</question>
input phosphor screen 
made out of cesium iodide 
purpose to absorb xrays into &amp; emit light photons

<question>
what is the second layer of the II
what is this layer made of
</question>
photocathode layer 
cesium &amp; antimony compounds

<question>
what are the two portions at the top of the II
what structure is between the anode and the photocathode parts of the II  
</question>
the anode then the output fluorescent screen
electrostatic lenses

how does fluoro work
after beam exits patient it strikes the <strong>input phosphor screen</strong> of the II (which absorbs photons to light
these photons then strike the <strong>photocathode</strong> layer which is in contact with the input screen (also absorbs light photons and <strong>emits electrons)
</strong>electrons are shot thru the II from <strong>photocathode </strong>and strike the <strong>anode and output screen
</strong>then output screen absorbs electrons and emits light photons (50-75x as many more light photons now created)

<question>
what is the purpose of electrostatic lenses 
where are they located
what focuses the stream in this direction
</question>
they are used to accelerate and focus electrons to the anode and output screen 
located in the II just out side of the divergence of the stream of electrons heading to the anode output side
the opposite charges between the electrons and the lenses

<question>
voltage:
potential voltage:
</question>
energy that sends the electrons to the output side
the difference of energy in electrons from the photocathode side to the output screen side

the output phosphor screen is composed of
zinc cadmium sulfide

how else can the xray tech operate the the fluoro machine
by a foot pedal (dead man type)

back i nthe day what did radiologist have to do before fluoring
they had to make their eyes adapted to the dark because image brightness was very low