Ch 12 Test 1 spring semester Flashcards
Two parts of radiographic film?
Base
Emulsion
The medium that converts the X-ray beam into a visible image
The image Receptor IR
What does emulsion consist of?
Gelatin and silver halide crystals
Photoelectrons and silver ions are attracted to these sensitivity centers to form ?
The latent image center
The size and distribution of silver halide crystals effect what ?
The film speed
What happens when light crosses over the base in the image intensifying screen?
Increased blurring in the image
But images are more blurred than without the screens
What is a safelight ?
A light for the Lightroom to provide enough light to illuminate the room without damaging the film
The use of intensifying screens with film allows for what?
Reduced technique=reduced patient dose
The silver bromine and iodine atoms are fixed together to form?
Crystal lattice on ion form
Silver is positive
Bromine and iodide are negative
An atom that has too many or too few electrons and therefore has an electron charge
An Ion
The group of silver atoms;
Where visible quantities of silver form during film processing to create the image
Latent image center
A device that converts energy of the X-ray beam into visible light
The intensifying screen
THe active layer of the intensifying screen
The phosphor
Converts X-ray beam into light
The Phosphor
The layer farthest from the radiographic film
The base
The emitted visible light
Luminescence
The wavelength of the emitted light is determined by
The level of excitation of the electron
During stimulation:
(X-rays)
after stimulation:
Flouro)
Fluorescence
Phosphorescence
Is on the base of the film to act as a mirror
Reflective layer
This occurs on our image with too little mAs
Quantum mottle
Increasing screen speed; causes more light.. thus giving our patient ??
Less patient dose!!
What reduces optical density in screen film?
Spectral matching
The use of screens- increase tube life but then reduces?
Patient dose
With fog, our geometric detail stays the same but our visual detail goes?
Down!! Because we have more density(the whole film is a different shade of grey)
Contrast resolution is determined by ?
Tissue absorption
Increased film speed, results in lower?
Detail.
Where do we see carbon fiber used in the radiology room?
On the table(couch)
What is the efficiency of rare earth screens vs calcium tungstate??
Rare earth is 20%
Calcium tungstate is 5%
The thickness of the crystals on the emulsion can affect what?
The film speed!
Double emulsion film can increase ?
Speed
After exposure to light(X-rays), the film becomes more ?
Sensitive
The conductor of heat on the tube is the ?
Anode
The source of electrons come from where in the tube ?
The filament which is in the cathode
The removal of an electron from an atom
Ionization
The energy of motion
Kinetic energy
The type of energy used in X-ray?
Electromagnetic energy
Energy emitted and transferred through space
Radiation!!
The orbital electron and the atom from which it separated is called?
Ion pair
And we measure these with a dosimeter :)
Gamma rays are from
X-rays are from
The nucleus
Electron cloud
Cosmic rays come from
Terrestrial rays come from
Sun and stars
Deposits of uranium radionuclides on earth
Barium platinocyanide is used in
Flouro!
When did Roentgen discovered X-rays
Nov 8, 1895
Standard units of measure
Mass length time
The subunit for exposure is??
The subunit for absorbed dose and effective dose ?
Air Kerma /coulomb
Joule (gray vs sievert)
Why is the K shell the only shell in Radiation X-rays?
Because of its binding energy!!
Occupies only 2 electrons in its shell
Same atomic # but different mass
Same atomic #, same mass
Isotopes
Isomers
What is the symbol for the atomic #
Z
Symbolizes #s of protons
Two main types of particulate radiation?
Alpha and Beta
Alpha is heavy!
Beta electron emitted from the nucleus
The non ionizing radiation used is?
MRI and ultrasound
Have no mass and no charge??
Photons!!
The unit for frequency?
Hertz (Hz)
Th speed of light =
Velocity
Two types of invisible light emitted by the sun?
Infrared
Ultraviolet
The only difference between X-rays and gamma rays?
Their origin
Inverse square law
Used to calculate amount of intensity of X-ray by increasing or decreasing distance
Radiopaque
Radiolucent
Total absorption (only bone)
Attenuation (bone muscle air)
What is the heel effect??
More #s of electrons exist on the cathode side bcuz that’s where the X-rays are created.
The anode side of the tube has less X-rays so you need to place the thicker body part on the cathode side.
3 types of electromagnetic energy?
X-rays
Visible light
Radiofrequencies
Unlike charges attract, while like charges repel
Electrostatic force
AC vs DC
Ac-back and forth electron flow
DC-electron flow in one direction
(Thus the transformer to change AC to DC)
Circuits -
Parallel vs series
Solenoid-
Parallel- new Xmas lights
Series-old xmas lights
A coil of wire
Silver ion crystals are converted to atomic silver
Film processing
Latent image is converted to visible image
Developing
Removes silver halide from emulsion and hardens the gelatin
Fixing
The wetting and stop bath are both not included in
Autoprocessing
Reducing a silver ion to matallic silver is called?
The reducing agent
Th action when 2 agents work better together than alone is called?
Synergism
The amount of Time it takes to process manually vs autoprocess?
1 hour manually
90 seconds auto
What is a preservative used for?
It is in the developer to keep it clear and to control the oxidation in the developer
The lack of sufficient glutaraldahyde (the hardener) May be the biggest problem with
the auto processor
Film development has 3 characteristics which of are very important:
Time
Temp
concentration
The temperature in the developer is ?
N wash water?
95*
And in wash water 5*
Inadequate washing leads to what in the film?
Fading and browning
Aka (hypo retention)
What stops the electrons?? As energy is released n produces X-rays?
The anode (aka target)
What are the crossover racks in the processor?
Transports the film to one step to th next step (buckets)
The fixing agent removes what?
Undeveloped silver ions
The activator does what?
It’s made of acetic acid and neutralizes the developer and stops its action
The purpose of the autotransformer?
To select KvP,
One winding, one core
Serves as both primary and secondary coils
The binding energy to an electron to a nucleus is higher for a _______ shell than an M shell
L shell
