Radiographic Imaging Mod 4

_______________ is the positive side of the x-ray tube, serves as a target surface for electrons from the filament and conducts high voltage from the cathode back to the generator

anode

_______________ is the reduction in the number of x-ray photons as the beam passes through matter

attenuation

_______________ is the number of nuclear protons in an atom unique to each element

atomic number

_______________ is the amount of energy needed to remove the electron from the atom

binding energy

_______________ is the negative side of the x-ray tube, produces electrons to accelerate to the anode

cathode

_______________ is the weighted average atomic number for the different elements of a material

effective atomic number

_______________ is the small coil of thin tungsten wire

filament

_______________ is an unintended optical density on an image that reduces contrast due to light/chemical exposure

fog

_______________ is the number of waves that passes a particular point in a given time frame

frequency

_______________ is the initial photon from the primary beam

incident photon

_______________ is the initial electron from the cathode

incident electron

_______________ is an atom that has gained or lost an electron

ion

_______________ is a small bundle of energy (electromagnetic energy) aka quantum

photon

_______________ is an artifact caused by unintentional exposure to radiation

radiation fog

_______________ is x-rays scattered back in the opposite or right angle direction to the primary beam

scatter radiation

_______________ is penetrating, ionizing electromagnetic energy

x-ray

_______________ is made between anode and cathode's electrons, so it is why the electrons move across the x-ray tube at _______________ speed

potential difference, 1/2 the speed of light

99% of photon production is _______________ and 1% is _______________ and _______________

infrared, characteristic and bremstrallung

_______________ shows photon emissions at their energies, majority of photons are at _______________ of set kV

emission spectrum, 1/3

_______________ when incident photon travels through patient w/o hitting anything - creates black spots on radiograph. What makes our pictures. It has no charge, no ionization

transmission

more transmission happens when _______ atomic parts, ________ kVp (travels straighter), and _______ parts

low, high, thin

less transmission happens when _________ atomic number, ________ kVp, and _________ parts

high, low, thick

transmission is dependent on __________/__________

kV, energy

_______________ gets absorbed by either knocking out electron or trying to knock out electron. Mainly happens with ____-shell electrons. Loses all its energy knocking out electron.

photo-electric effect, k

a _______________ is a bundle of energy, so it doesn't exist anymore when hitting k-shell electron in PE effect. The energy is transferred to the electron that was knocked out, so photon can't make it to film and this creates _______________ spots on radiograph

photon, white

_______________ _______________ in photo-electric effect lose all their energy or it's scatter

incident photons

more photo electric = _________ kV, _________ parts, and ________ atomic number

less, thicker, higher

less photo electric = ________ kV, ________ parts, _________ atomic number

more, thinner, lower

for PE it is the incoming photon _____ shell binding energy = ______________

minus, electron lost's energy

_______________ is when patient's make radiation/photons from the empty shell that is filled after losing it's. electron. (Characteristic radiation made inside what we radiate)

secondary radiation

classical scatter or coherent is not _______________ or doesn't make atom lose electron. It is considered this because it only happens at ______ keV or less. (Does not get through)

ionizing, 10

secondary radiation undergoes another PE affect with in _______________ of patient tissue

1-2 cm

_______________ goes in any direction

scatter

in classical or coherent scatter, either the electron in a shell is jiggled and releases the same amount of energy to return to equilibrium which is _______________ or the whole atom is jiggled by incident photon and releases same amount of energy to return to equilibrium which is _______________ (the energy released from both is a different photon than the incident photon)

thompson, rayleigh

_______________ radiation is from the tube

primary

_______________ is caused by incident photon's energy not being fully absorbed or trasferred.
-why we wear lead shielding
-same photon from x-ray tube

compton scatter

_______________ is the number one occupational dose source

compton scatter

in _______________, the majority of the time is happening on outershell electrons due to _______________

compton scattering, low binding energies

_______________ is caused by forward scatter which lowers contrast, or ruins white areas

radiation fog

_______________ happens after vacant electrons get filled

secondary radiation

more scatter and less contrast happens when....
_______ matter
________ part density
_________ field size
_______ kV

more, more, more, more

scatter _______________ contrast

decreases

scatter can also be called _______________

noise

does atomic number affect scatter?

no, but part density does

thicker/bigger patient = _______________ scatter (comptom)

more

secondary radiation travels _____________ than undergoes ____________

1-2 cm, Photoelectric effect

_______________ scatter happens when incident photon loses less energy, _______________ scatter happens when incident photon loses half it's energy, _______________ scatter happens when incident photon loses more energy

forward, side, back

_______________ scatter is what tech is most worried about for occupational dose

side

_______________ absorption is based off of object/part thickness, compositon

differential

_______________ is the average of atomic number's of the elements something is made out of

effective atomic number

_______________ effective atomic number is 6.46
_______________ effective atomic number is 7.51
_______________ effective atomic number is 7.64
_______________ effective atomic number is 7.78
_______________ effective atomic number 12.31

fat, water, muscle, air, bone

why does air look different in radiographs than water and muscle whose effective atomic number are about the same?

it is in a different state (gaseous)

osteolytic = ________ transmission or go ________ in technique. Less PE

more, down

osteoblastic and edema = __________ photoelectric effect or go _____ in technique. Absorption = _____ Less transmission

more, up, more

___________ kV = more compton scatter

higher

Differential absorption

Different degrees of absorption in different tissues that results in image contrast and formation of the x-ray image (thick v.s thin tissue)

In compton scatter _______ have energy left over after knocking out ____ _____

photons, outer shells

Back scatter has ______ energy left

less

Side scatter has _____ energy left

half

Forward scatter has _____ energy left

majority

Compton scatter ________ patient dose, _______ bystander dose, and _______ image quality

increases, increases, reduces