Safety & Intro Flashcards
The particle of an atom that has an negative charge is the:
Electron
What are some of the physical properties of X-rays?
- damages tissue
- variable wavelengths
- causes some substances to fluoresce
X-rays are defined as a form of _____________ radiation.
Electromagnetic
As the wavelength of X-ray photons shorten, the energy of the X-ray beam will:
Increase
The ratio of hear generated from an X-ray is:
99%:1%
The primary source of radiation
The patient
What thing on the X-ray machine limits the size of the primary beam ad reduces secondary exposure?
Collimator
Because of the heel effect, a technician would need to:
Place the thickest part of the patient toward the cathode side of the X-ray tube
The workplace program that ensures radiation exposures are low as possible:
ALARA
Minimum age for a person to take X-rays
18 years
Minimum led thickness requirement for protective gloves/aprons :
0.5mm
A grid with a ratio of 10:1 absorbs:
More scatter and requires greater exposure factors than a 5:1
KVP controls the ________ of the X-ray machine
Quality
The mAs controls the ______ of the X-ray machine
Quantity
The transformer that controls the temp of the filament
Step-down transformer
Exposure factor that accelerates the electrons from the cathode to the anode:
KVP
Controls the temp of the cathode filament:
mA
What is Sante’s rule?
[2xthickness(cm)] + 40
If you change SID, you must also change:
mAs
The acceleration of the electrons and their ultimate striking energy is determined by the :
Kilovoltage (KVP)
Minimum distance in feet for a safelight to be away from the work site in the dark room
4 feet
If using blue/green sensitive films, you should also use a ____ safety light.
Red
Main purpose of X-ray developer:
Convert the exposed silver halide crystals into black metallic silver.
Main purpose of fixer
Clear away unexposed, undeveloped silver halide crystals.
Maximum intensity of safelight bulb
15 watts
To get more density on film you should ______ KVP and _______ mAs.
Increase kVp, do nothing to mAs because it doesn’t affect density
Rare-earth screens are sensitive to:
Green range of light
A radiograph is dark, bones are grey, what should you do?
Decrease KVP
The pH of the fixer chemicals is:
Acidic
Ideal temp for the chemicals in manual radio graphic process:
68 degrees F
How should you store films?
Away from chemicals and sources of ionizing radiation , 10 - 15 degrees C, and have a humidity of 40-60%
Non screen film is often used for X-rays of the ________.
Teeth
An X-ray exposed to light and developed appear:
Black
An x ray developed before exposure to radiation appears:
White
A new X-ray taken directly from the box is:
Clear
Things about fast films:
- large silver crystals
- has grainier image, less definition
- less latitude in exposure factors
If radiograph is too light and image is under penetrated you should:
Increase KVP 10-15%
If radiograph is too dark and has adequate penetration you should:
Decrease mAs 30-50%
If film is too dark and Is over penetrated you should:
Decrease KVP 10-15%
You should decrease mAs by 50% if a dog is :
Neonatal
mAs should be increased by 50% if your takin a X-ray of a :
Animal with ascites
When can you take a tabletop X-ray?
When area of interest is 10cm thick
X-ray film cassettes have what kind of screens inside them that glow when irradiated?
Intensifying screens
What can you do to minimize X-ray radiation the most?
Narrow the collimator
When radiographing a distal extremity, a _______ scale of contrast is best.
Short
When you double the mAs, you _______ the intensity.
Double
What is a latent image?
Image on the film before exposure
What’s the proper order for manual processing of an X-ray
Develop, rinse, fix, wash, dry
What light sensitive chemical is in the X-ray film?
Silver halide crystals
What is non screen X-ray film most sensitive to?
X-ray radiation
What type of X-ray film produces greatest detail?
Low speed
What X-ray film has greatest latitude, without change in density?
Slow
What’s an advantage to using screen X-ray film over non screen film?
Requires shorter exposure times
A cloud of negative ______ radiation forms at the _______ side of the X-ray tube when the _______ is heated.
Electron, cathode, filament.
The filament is made of ________ and housed in the ___________ ____, which directs electrons towards the anode side of the X-ray tube.
Tungsten
Focusing cup
Anode
X-ray are produced when fast moving ___________ collide with matter, which is achieved when they hit the ________ of the target.
Electrons
Anode
Density is the degree of __________ on the radiograph.
Blackness
Electromagnetic waves behave as a __________ as well as a ______.
Partical as well as a wave.
Stationary anode is found in a ________ machine.
Mobile
Which type of anode produces a clearer image?
Rotating anode
High contrast radiographs are also known as ______ ______ and are needed for _______ studies.
Short scale
Bone
What does SID stand for? What’s the standard?
Source imaging distance
Standard = 40in
What is the device that is used to measure the area of interest? Are animals measured in cm or in?
The caliper, measured in cm.
2 factors that affect density of film.
Number of X-rays that reach the film
Developing time
Penetrating power
What’s a grid? Where is it located?
A device that absorbs scatter radiation. Located in Bucky tray.
What’s a dosimeter? What’s the most common one?
A device that calculates the amount of radiation that is absorbed by a person. Most common is dosimeter badge. [clip on you, near the neck]
What PPE’s do you wear every time you take a x ray?
Gloves, led apron, and thyroid shield.
3 methods of reducing exposure
Reduce retakes
Rotate the people who restraint
Only the people helping stay in room
Under exposed , too light
Increase KVP or mAs
Overexposed , too dark
Decrease KVP or mAs
X-rays have adequate penetration
Change mAs by 30-50%
X-rays inadequately penetrated
Change KVP by 10-15%
Low contrast is for
Soft tissue studies
What are the types of grids?
Parallel
Focused
Pseudo focused
Crisscross
What does MPD stand for?
Maximum permissible dose
What does ALARA stand for?
As low as reasonable achievable
Cells most sensitive to radiation:
Growth cells,
Cancer cells,
Reproductive cells.
Most common effects of excessive radiation are:
Somatic and genetic radiation
MPD of someone in a occupational job
0.05 sv/year
MPD for non-occupational job
0.005 sv/year
