Final Sememster 1 RT 2 Review Flashcards
The energy of motion
Radiation that is capable of removing an electron from an atom
Kinetic energy
Ionizing radiation
Material used for fluorescent in Flouro
Uses aluminum or copper to absorb low energy X-rays -in the tube
Barium platinocyanide
Filtration
Smallest particle of an element
Atoms that have same atomic # and different mass
Atom
Isotopes
Gamma rays come from
X-rays comes from
Nucleus
Electron cloud
X-rays and gamma rays are =
Photons
Radiology is considered a ________ occupation
Original atom and the negative electron that was removed from orbit
Safe
Ion Pair
Charge of Cathode=
Charge of Anode=
Non ionizing radiation
Negative
Positive
Sono and MRI
X-rays and gamma rays have what charge??
No mass and no charge
An atom in a normal state has s charge of
Zero!
Velocity=
Static Radiology
Dynamic radiology
Speed of light
Still image
Flouro/motion
Intensity =
Quantity!
The unit of energy:
Absorbed dose:
Radiation equivalent man:
Joule
Rad
Rem
The source of electrons come from what target mAterial in tube
Cathode
Tungsten
Half value layer
Quantity of thickness in built in filtration that reduces # of X-rays in 1/2
The largest source of natural radiation ?
Radon
Who developed the Flouro scope?
2 types of particulate radiation?
Thomas Edison
Alpha and Beta
The date of discovery of X-rays by Wilhem Roentgen ?
November 8, 1895
The unit of radiation exposure ??
Air kerma /Gya (R)
Smallest quantity of electromagnetic energy
Photon
Rate of rise and fall on sine wave
Distance from one crest to the next
Frequency (how many waves)
Wavelength (distance between waves),
These two are most important!
If 50kVp is coming out of the wall/tube what is going to the patient??
Up to 50kev
Reduction of the # of X-rays in certain tissues. X-rays absorb differently in different tissues
Attenuation
What conversion will we look for when a question asks about mR??
And about mAs ?
Inverse square Law
Direct square law
Properties of electromagnetic energy
Frequency
Wavelength
Velocity amplitude
Sunlight consists of 2 visible light; what r they
Infrared
UltrViolet
The microwave has very ______ wavelengths
Short
X-rays and gamma ray are equal energy only they differ by their
Origin
Velocity ===
Constant
(electric potential) Volts are converted to
(Electric current)Amperage is converted to
KVP
mA
Series circuit vs parallel circuit
Direct current DC vs ALternating current AC
All circuits are on one line along same circuit (old Xmas lights) one goes out they all do.
* New Christmas= parallel
Electrons flow in same direction
Electrons flow back and forth
The law of electrostatics:
Like charges _______
Unlike charges ________
Electrostatic charge is a
Repel
Attract
Coloumb
Device used to changes electric current
Transformer
Only works with AC
Weakly repelled or attracted
Strongly attracted to magnetic
In between attraction and repelling
Diamagnetic
Ferromagnetic
Paramagnetic
A coil of wire
Solenoid
Eddie current
Electrons travel outside the wire; on the innermost curve of that wire
Like ripples in the water
The autotransformer -
Rectification
Has one winding and one core!
Converts AC >DC
All electric circuits are low voltage to prevent
Shock
We don’t use a focal spot with high mA for such as Flouro because
Using the focal spot increases heat in the tube as does an increase in mA
The control console contains:
Autotransformer Kvp selectors mA selector but NOT mA meter Line compensation Tap windings
The high voltage section contains:
mA - post reader
Kvp-pre reader
Step up transformer Step down transformer Focal spot selector mA meter Rectifier
The X-ray circuit contains 3 sections
Control console
High voltage generator
X-ray tube
X-rays are emitted —
_____ is used as an insulator to prevent electric shock
Isotropically
Oil
The glass used in an X-ray tube is
Pyrex
To withstand the heat
The filament emits electrons when it is heated (boiling off electrons) this is called
Thermionic emission
Tungsten vaporization is a common cause of tube failure and can cause ______
Tube arching
Selection of a small or large focal spot is selected by ____
The mA station selector
The focus Cup is on what side of the tube and has a charge of
Cathode side and is negatively charged
The greater the angle of the Anode tube; the greater
The Focal spot (beam)
The cathode side of the tube is more ____ than the anode side of the tube
Intense
Remember tube rating charts!
On or below the line of interest!!
The electron from cathode to Anode is called
The projectile electron
Outer shell electrons, fill the void of an inner shell to produce a characteristic X-ray; what shell causes this?
It is characteristic because of its
K shell
Target material (tungsten)
These X-rays are produced when a projectile electron is slowed by a magnetic/nuclear field.
Bremsstrahlung
Brems are all low energy X-rays
Characteristic are
X-rays that are 69/70 kvp! Only !!
Exposure Intensity Density #s Quantity
Described words for mAs or kvp
mAs
Quantity
Penetrability Dosemter/ion pairs Kvp HVL Quality
Are all words that describe mAs or kvp
Kvp !!
Quality
Most X-rays are Brems and are between
20-150kvp
Long scale; low contrast!! (High kvp)
Short scale; high contrast (low kvp)
Filtration _______ pt dose
A grid _______ pt dose
Lowers
Increases
Other names for coherent scattering
Classical, Thompson, Rayleigh
The incident X-rays that effect the occupational dose?
The incident X-rays that effect the patient dose ??
Compton scattering
Photoelectric effect
Compton scattering interacts with the _____ shell electron
Photoelectric interacts with the _______ shell electron in patients body
Outer
Inner
2 electrodes; used to be the vacuum tubes but now is made of silicon
Diode
The source of X-rays in X-ray tube
Are from the focal spot
The first working computer
Th first general purpose computer
Colossus
ENIAC
Computers were first developed with
Vacuum tubes
Oldest computer language
Fortran
Bit
Byte
Nibble
Chomp
0, 1
8 bits
1/2 byte
2 words
Bootstrap on the computer means
Program to turn on computer
Manipulates data and carry out instructions on the computer; memory
CPU
Standard method of storage of images
DICOM
Digital imaging and communications in medicine
Tele-radiography
Transfer of data to remote sites of radiologists to view images
4 characteristics of medical image
Spatial resolution
Contrast resolution
Noise
Artifacts
Parallax effect =
Penumbra
Ability of imaging system to render objects into different sizes and shapes
MTF
Spatial Resolution=
Detail
The greater the pixels the better the detail
We use a ______ to remove fog!
Grid
Photopic
Scotopic
Bright light-comes of eye
Dim light -rods of eye
RIS
Voltage variation causing lines
Radiology information system
Line noise
Cathode ray tube (CRT) vs LCD
CRT =scanned beam;Curved face
LCD = active matrix; flat faced
If you have quantum noise; you don’t have enough
mAs
What is the Activator for CR?? CR can not be possible with out this
Eu (europium)
What is CCD?
Charge couple device
Silicon based semi conductor
The fill factor is sensitive to X-rays at what percentage
80%; 20% does not contribute to image in DR
The number of gray shades that an imaging systems produce
Human eye can detect how many shades of gray
Dynamic range
30 shades of gray
Spatial resolution is determine by
MTF
Bus lines; conductors =
TFT (thin film transistor)
Light emission through stimulation
Light emission during stimulation
Fluorescence
Phosphorescence
Converts electric energy to mechanical
Converts mechanical to electrical energy
Motor
Generator
Th largest man made source of ionizing radiation?
Diagnostic X-rays!!
The unit used for
Absorbed dose, biological effects, and ionizing radiation is
Rad
100R= 1 rad Gya
100mR= .001 Gya
Rad =Gya also
The unit used for equivalent man, occupational or population dose is
Rem
100 Rem =1 Sv
100 mRem =.001 Sv
The source of electrons come from
The source of X-rays come from
The filament
The focal spot
