KI 1

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What is an x-ray?: A form of energy: Electromagnetic radiation that has ionizing properties.
X-ray's qualities as an electromagnetic radiation. (List 8): 1. travel in waves
2. possess great energy in short wavelengths
3. travel at the speed of light
4. travel in straight lines
5. can penetrate objects
6. affect photographic film
7. can cause biological changes
8. can cause certain objects to fluoresce
3 examples of electromagnetic energy: 1. TV and radio waves
2. radar
3. infrared waves
X-rays are a ____ energy form: radiant
______ is a method of transporting energy through space: Radiation
______ is determined by the distance between 2 amplitudes: Wavelength
Shorter wavelengths carry ______ penetrating power than longer ones: greater
X-rays have the ability to _____ matter: ionize
________ is the removal of an outer electron from an atom so that the atom is left with a positive charge.: Ionization
Ionization of a cell will result in its _____ or _______.: alteration
destruction
Ionization can cause _________ near the cells which can affect their ability to function or result in their death.: Ionization
An X-ray _____ is require to produce a controlled beam.: tube
List 4 major parts of an x-ray tube: 1. Cathode
2. Anode
3. Glass envelope
4. Lead housing
______ is the negatively charged electrode of an x-ray tube: cathode
______ is the positively charged electrode of an x-ray tube: anode
Cathode of an x-ray tube contains the following 2 parts: _______ and ________: filament
focusing cup
______ is 1 or 2 tungsten wires which serve as an electron source when heated: Filament
______ is a recessed area in the cathode where the filament lays: Focusing cup
______ directs the electron flow towards the other side of the tube: Focusing cup
List 4 parts within the anode: 1. target
2. focal spot
3. stationary anode
4. rotating anode
_____ is a beveled tungsten area mounted on a copper cylinder. It provides a "target" for the electrons to bombard and interact with its atoms and a place for heat to dissipate: Target
______ is the small area of the target where the electrons actually hit: Focal spot
_____ are found in dental and small portable radiography units. The tungsten target area is embedded on a cylinder of copper, with the face of the target angled down toward the window: Stationary anode
________ is disk shaped and rotates on an axis through the center of the tube.: Rotating anode
______ is a vacuum tube that encases the anode and cathode: Glass envelope
______ is to protect the glass envelope and prevent escape of stray radiation: Lead housing
X-rays are produced in the tube, when the _________, electrons become excited and a _____ of negatively charged electrons are produced.: filament is heated
cloud
The filament is heated by a low-energy circuit measured by _________.: milliamperage (mA)
The _____ the mA, hotter the filament, th emore electrons are produced: higher
The ______ houses the filament and directs the beam of electrons towards the anode.: focusing cup
The potential difference between the anode and the cathode is measured in ______: kilovolts
______ (___) measures the maximum energy available at that kv setting.: Kilovoltage peak (kvp)
The _____ the kvp, the greater the difference in charge, the faster the electrons accelerate across the tube.: highter
When the accelerated electrons collide with the atoms of the target, energy is released in the form of _____ (____%) and ______ (___%).: heat (99%)
x-rays (1%)
Primary beam contains the following 2 things:: 1. primary radiation
2. secondary radiation
Primary beam consists of _________ which is the useful beam of photons that will help to create an image on film.: primary radiation
Primary beam contains ________ which is weaker x-rays that do not contribute to the formation of an image: secondary radiation
__________ is produced when primary x-rays interact with matter and lose energy: secondary radiation
_______ is a form of secondary radiation that has lost energy and has changed direction.: scatter radiation
List the 3 things that happen when x-rays leave the tube and strike an object.: 1. penetrate the object
2. absorbed by the object
3. deflected by the object
What is the most common cause of x-ray tube failure?: Filament evaporation
_______ is a decrease of x-ray intensity on the anode side of the x-ray beam due to the anode target angle.: Heel effect
The intensity of the primary x-ray beam is greater toward the _____ side of the x-ray beam.: cathode
_________ affects the overall quality of the x-ray because of the formation of penumbra.: Focal spot size
_________ is determined by filament size which is predetermined by the manufacturer and target: Focal spot size
_________ is the size of the focal spot when viewed directly through the window of the tube: Effective focal spot size
_______ determine penumbra production and therefore overall radiographic quality and affect anode damage.: Effective focal spot size
__________ is the size of the focal spot when viewed perpendicular to the surface of the target.: Actual focal spot size
_____ determines anode heat capacity and influences the heel effect: Actual focal spot size
________ is a device which limits or restricts the size of the primary beam as it is emitted from the tube.: Collimator
________'s purpose is to absorb the primary beam and reduce the field of exposure: Collimator
By decreasing the scatter radiation, you'll achieve 2 things:: 1. improve radiographic quality
2. reduces operator exposure
3 things collimator will not do: 1. not focus the beam
2. not concentrate the beam
3. not redirect the beam
Adjustable lead shutters is a type of __________: Collimator
___________ has 2 pairs of moveable lead shutters operating in opposite directions: Adjustable lead shutters
Collimator is often described as "______" because of the ______: coning down
cones
When to use collimation: 1. Always
2. for increased detail of a specific area or part
3. AAHA and radiation safety bureau will inspect for routine collimation
_________ is a sheet of aluminum absorber placed at the window of the tube housing: Aluminum filtration
___________ is used to absorb low level radiation from the primary beam: Aluminum filtration
_______ supports the x-ray tube: Tube stand
_____ is alternating strips of lead and plastic set on edge, and encased in a flat aluminum case of various sizes similar to x-ray cassettes. It is then placed under the table, between the patient and the x-ray film.: Grids
Purpose of ______ is to limit the exposure of the film to scatter radiation thereby increasing radiographic quality.: Grids
_________ causes gray fogging of the film to occur: Scatter radiation
The lead strips of grids absorb the _________ as it bounces off the object.: secondary radiation
The __________ of grids allow the primary radiation to pass through to the film.: interfacer strips
4 types of grid: 1. Linear
2. Crossed
3. Focused
4. Parallel
_____ is the relationship of how tall the lead strips are to how far apart they are placed from each other: grid ratio
________ is a method of transporting energy through space and is distinguished by its wavelength, frequency, and energy.: Electromagnetic radiation
_____ consist of small particles called protons, neutrons and electrons.: Atoms
In 1895, _______ discovered x-rays.: Wilhelm Roentgen
The porpose of the x-ray tube is to _____________.: produce a controlled x-ray beam.
5 elements necessary for x-ray production: 1. A source of electrons
2. A method of accelrating the electrons
3. An obstacle-free path for the passage of high-speed electrons
4. A target in which the electrons can interact, releasing energy in the form of x-rays
5. An envelope to provide a vacuum environment, eliminating the air molecule obstacles from the electron stream and preventing rapid oxidation of the elements.
The purpose of the cathode is to _____________: provide a source of electrons and direct these electrons toward the anode.
The filament is constructed of tungsten because of its __________: high melting point and high atomic number.
List 2 types of anodes: Stationary anode
Rotating anode
Filaments located in an x-ray tube: a. are made of molybdenum. b. must have a low melting point and low atomic number. c. are found in the anode. d. emit electrons when heated.: d. emit electrons when heated.
The node's tarted: a. is composed of tungsten. b. reaches temperatures in excess of 1000C during x-ray production c. usually has a copper base d. All of the above: d. All of the above
Which of the following are limitations of the stationary anode? a. The target is made of tungsten. b. It is unable to withstand large amounts of heat. c. If the tarted becomes pitted, radiographs appear darker. d. It is limited to a l: b. It is unable to withstand large amounts of heat.
How can the technician help to prolong the life of the filament in the x-ray tube? a. Enter the proper exposure settings int he control panel before the final positioning of the animal. b. Leave the x-ray unit on at att times to ensure that the: a. Enter the proper exposure settings int he control panel before the final positioning of the animal.
Which of the following are possible effects of excessive heat within an x-ray tube? a. Bearing failure and decreased anode speed b. Roughened target surface c. Arcing d. All of the above: d. All of the above
True or false: A small amount of air within the glass envelope is beneficial because it helps to dissipate heat.: False: Air molecules interfere with the path of electrons, thus decreasing the number of electrons reaching the target.
Veterinary patients have a tendency to move while being positioned for radiographs to be taken. The radiographer should help to safely prevent artifacts of movement by: a. using the shortest exposure time possible. b. altering the direction in: a. using the shortest exposure time possible.
Which of the following is recommended to reduce unnecessary irradiation of the patient or persons restraining the patient and to decrease scatter radiation? a. Opening the collimator as wide as possible b. Placement of a lead apron over the are: d. Adjustment of the collimator so that the smallest field size possible is used
X-ray tube ratings are based on target angle, focal spot size, electrical current (single- or three-phase operation), and: a. rectification. b. its alloy composition. c. anode speed. d. type of filament.: c. anode speed.
The advantages of using an x-ray machine with a three-phase generator as opposed to a single-phase generator include: a. creation of more low-energy electrons bombarding the target, thus producing less heat. b. use of shorter exposure times bec: b. use of shorter exposure times because more power is available to the x-ray tube per unit time.
The negatively charged particle of an atom is the: a. proton b. neutron c. electron d. nucleus: c. electron
As x-rays pass through materials, they have the ability to: a. cause some substances to fluoresce (emit visible light) b. completely remove an electron from an atom, leaving the atom positively charged. c. cause chemical changes that can k: d. All of the above
Which of the following statements is true? a. X-rays with longer wavelengths penetrate farther than rays with shorter wavelengths b. X-rays with shorter wavelengths penetrate farther than rays with longer wavelengths c. Electromagnetic rad: b. X-rays with shorter wavelengths penetrate farther than rays with longer wavelengths
Electrons travel: a. toward the cathode in an x-ray tube b. away from the anode in an x-ray tube c. toward the anode in an x-ray tube d. within the nucleaus of an atom: c. toward the anode in an x-ray tube
In x-ray tubes, the majority of energy produced by the movement of electrons is in the form of: a. light b. heat c. sound d. x-ray energy: b. heat
On the electromagnetic spectrum, in relation to visible light, x-rays: a. have a longer wavelength b. have a lower frequency c. have a shorter wavelength d. are closer in wavelength to infrared rays than light waves: c. have a shorter wavelength
Bundles of energy that travel in a wave are called: a. protons b. photons c. quanta d. Both b and c are correct: d. Both b and c are correct
True or false: X-ray electromagnetic radiation travels in a straight line whose direction can be altered: True: The new direction, however, is also in a straight line
True or false: A radiogrraph is synonymous with an x-ray: False: A radiograph is the radiographic record of an object on film produced by the passage of x-rays, a form of electromagnetic radiation, through that object.
Which of the following is a type of somatic damage caused by radiation? a. Gene mutation b. Cataracts c. Sterility d. Non of the above: b. Cataracts
Which statement is true? a. The body's cells are all approximately equally sensitive to radiation b. Ionizing radiation only damages chromosomal material (DNA) within reproductive cells c. Chemical restraint of veterinary patients is prohi: d. Genetic damage is not detectable until future generations are produced
What is the upper limit of exposure that an occupationally exposed individual may receive according to state and federal regulations? a. 0.5 Sv/year b. 100 rem/year c. 0.05 Sv/year d. 0.005 Sv/year: c. 0.05 Sv/year
All of the following are true except: a. animals' cells are not as susceptible to damage from irradiation as human cells. b. radiation can affect the body's ability to produce red and white blood cells. c. exposure to radiation can affect: a. animals' cells are not as susceptible to damage from irradiation as human cells.
A film badge: a. is a type of pocket ionization chamber b. is a type of dosimeter designed to monitor the actual amount of radiation received c. must always be worn on the collar d. should always be submitted weekly to determine the l: b. is a type of dosimeter designed to monitor the actual amount of radiation received
What type of dosimeter can be stored for years, maintains its information, and can be reused? a. Pocket ionization chamber b. Collimator c. Thermoluminescent dosimeter d. Film badge: c. Thermoluminescent dosimeter
Which of the following statements is true? a. Veterinary personnel who restrain animals for radiographs are often exposed to the primary beam b. Scatter radiation can be reduced by the collimator c. Aluminum filtration helps to increase so: b. Scatter radiation can be reduced by the collimator
Scatter depends on: a. the intensity of the beam b. the composition of the structure being radiographed c. kilovoltage (kVp) level d. All of the above: d. All of the above
The most conclusive method used to inspect leadlined gloves and aprons for cracks and defects is: a. taking a radiograph of it. b. holding it up to the sunlight or a bright light c. inspecting it manually d. Both b and c are correct: a. taking a radiograph of it.
What is the thickness of the lead-impregnated rubber lining protective apparel in veterinary radiography? a. 1.0 cm b. 10 mm c. 0.5 mm d. 0.5 cm: c. 0.5 mm
List the tissues most sensitive to radiation-induced damage: Rapidly dividing cells, bone, lymphatic, dermis, leukopoietic, hemopoietic and epithelial tissues
State which personnel are prohibited from assisting in radiographic procedures: Persons younger than 18 years of age

Pregnant women
State the 2 types of tissue damage that can occur from exposure to radiation: Somatic damage

Genetic damage
Define maximum permissible dose (MPD) and name the organization that is responsible for setting dose limits: MPD is the maximum dose of radiation that a person may receive in a given period.

National Committee on Radiation Protection and Measurements (NCRP)
List and define the units of radiation exposure for absorption: Gray: the unit of absorbed dose.
Sievert: Gray * quality factor
State the MPD for occupationally exposed personnel: Up to 0.05 Sv/year
List and describe the 3 types of personal exposure dosimeters: Film badge: consists of a plastic holder that contains a radiation-sensitive film in a lightproof packaging

Posket ionization chamber: consists ion chamber and electrometer, which can be read immediately to determine the amount of exposure

Thermoluminescent dosimeter: consists a chamber containing special compounds that become electrically altered by ionizing radiation
State the 3 primary methods by which personnel are exposed to radiation during radiography: 1. exposure to the primary beam
2. exposure from secondary radiation
3. exposure from "leakage" radiation from the tube housing
List the practical methods that personnel can use to reduce personal exposure during radiography: 1. Restrict exposure to the primary beam
2. Restrict exposure to scatter radiation
3. Restrict re-takes
State the proper maintenance protocol for protective apparel: Hang aprons vertically over a round surfae or laid flat

Glove should be placed on vertical holders
_______ damage occurs to the person's body while that person is still alive: Somatic
Examples of somatic damage: cancer, cataracts, aplastic anemia and sterility
Injury severity depends on ____ and _______: dose rate
percentage of body exposed
_____ damage occurs as a result of injury to the person's reproductive DNA, resulting in gene mutation: Genetic
Measurement of radiation in old school: 1. Roentgen
2. RAD
3. Rem
Measurement of radiation in new school: 1. Gray
2. Sievert
An international unit of radiation based on its ability to ionize atoms as it passes through matter: Roentgen
A unit of absorbed dose, how much radiation is absorbed by the tissues: RAD
Unit of measurement that relates to the biologiccal effect of radiation: Rem
For veterinary applications, 1 Roentgen = ____ = _____: 1 Rad
1 Rem
Replaces the rad. Unit of absorbed dose.: Gray (Gy)
1 Gy = _____ rad: 100
Replaces Rem: Sievert (Sv)
1 Sv = _____ Rem: 100
In california the whole body MPD =: 5 rem / yr
California MPD for skin and extremities: 50 rem / yr
California MPD for lens of the eye: 15 rem / yr
Accumulated dose cannot exceed _________: 5 * (n-18) where n = age at last birthday

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