Exam 1 Flashcards
what is resolution
sharpness/detail of an image
what are xrays
light–> energy–> not created only change forms
what kind of energy are xrays
electromagnetic
short wavelengths have
high energy
long wavelengths have
low energy
xrays are defined as having
no mass, no charge, velocity
how are frequency and wavelength related
inversley
what is the wave equation
speed of light= wave lengthxfrequency
short wave length must have what kind of frequency
higher freq
what is a heterogenous xray beam
mixed rays with different wavelengths
xray density is also known as
blackness
if the xray interacts with the film what is created
blackness
if the xray does not interact with the film
whiteness
blackness vs whiteness =
differential absorption
how are radiographic density and anatomic density related
inversley
which particle is least likely to cause double strand DNA to break
xrays
how is electromagnetic radiation produced
by a charged being accelerated and then decelerated
what other light is exactly like xrays only has a different origin
gamma rays
which particle has mass
alpha
2 protons
2 neutrons
ionization of alpha particle can be stopped by
paper
dead skin
alpha particles are only dangerous/ionizing if
swallowed or inhaled
alpha particles cause what kind of DNA damage
double strand
no way to repair
xrays cause what kind of DNA damage
indirect
single strand damage
second stand able to repair the damaged
what particles are negatively charged
beta particles
what is a direct effect
ionization of atomic DNA
few ionizations over long distance
what does indirect effect cause
formation of free radiclas
direct effect of xray occurs
in a DNA molecule
indirect effect of xray exposure is
free radical production
which particle is the most biologically damaging
alpha particles
they are so ionizing the give up their electrons in a short distance
which production process produces xrays when electrons shift binding energy levels
characteristic
What does bremsstrahlung mean?
Braking
What is the tube made of
Pyrex
As the shell number increases what happen to electron affinity
It weakens the further out you go
What are the layers of electron shells in the characteristic method?
K L M N O P
Which layer on characteristic method requires the most energy to displace the electron from orbit?
K she’ll
What is the amount of every to displace at the k shell?
69.53 kpv
Where does electron displacement occur?
Any level but the k is the only one with enough power to matter
What type of wave length do the shells create?
All but k create long wave lengths
In characteristic method what does the cathode electron do?
Kicks the k shell electron out of orbit
Once the k shell electron is removed what happens
The empty spot is filled with an electron from a further out shell
The process of dropping from high energy to lower energy produces what
A photon
What kvp must you set the machine to get a picture
70 kvp
How many useful X-rays are produced from tungsten?
5 all other transitions occur simultaneously but have very low energy. So low it won't make it to the film L-->k M-->k N-->k O-->k P-->k
What happens in the bremsstrahlung method?
Electron passes near nucleus
+ field charge of nucleus acts on electron
Causes electron to decelerate and deflect
KE lost this emits a photon
How many X-rays are produced depending on the kvp?
Zero to whatever the kvp setting is
Majority of X-rays will be what percent of the peak level set
30%
Which X-ray production process occurs when high speed electrons slow or stop
Bremsstrahlung
Which X-ray production process requires at least 70kvp in a tungsten target to produce useful X-ray
Characteristic
Which production process is responsible for the majority of xrays in a beam?
Bremsstrahlung
Because characteristic only produces 5
What is the highest possible kip for characteristic?
69.3kvp
What are the two types of current.
Ac and dc
What type of power is distributed by power companies?
Ac
What current produces X-rays?
Doc
What are the four types of rectifiers
Half wave
Full wave single phase
3 phase
High freq
What is the difference between single phase and three phase?
Single has one wire
3phase has three
Where are 3phase machines found
Hospitals
What is ALARA
As low as reasonably achievable
Which machine has 30-50% less patient exposure?
High freq
What is the purpose of a rectifier?
Change ac to dc
What is the most affordable and has the least patient exposure?
High freq
Which side of X-ray has the fewest X-rays?
Anode
Which side is fuzzy and dark
Cathode
Which side is geometrically sharp and light?
Anode
Where should anode be for 14x36 ap full spine
Up
Anode for ap t spine
Up
Anode for lat lumbar
Up
Anode for lat tspine
Down
Anode for lay cervical
Doesn’t matter
Anode for ap femur
Down
