Welcome to StudyStack, where users create FlashCards and share them with others. Click on the large flashcard to flip it over. Then click the green, red, or yellow box to move the current card to that box. Below the flashcards are blue buttons for other activities that you can try to study the same information.
Test Android StudyStack App
Please help StudyStack get a grant! Vote here.
or...
Reset Password Free Sign Up

Free flashcards for serious fun studying. Create your own or use sets shared by other students and teachers.


incorrect cards (0)
correct cards (0)
remaining cards (0)
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the Correct box, the DOWN ARROW key to move the card to the Incorrect box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

Correct box contains:
Time elapsed:
Retries:
restart all cards


Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Physics Test #1

Ch 1, 2, 3

QuestionAnswer
List 7 Characteristics of X-rays: * Invisible * Electrically neutral * No mass * Cannot be optically focused * Travel @ speed of light in vaccum * Form a polyenergetic beam * Can be produced in a range of energies * Can cause some substances to fluoresce
List 7 more Characteristics of X-rays * Travel in a straight line * Can cause some substances to fluoresce * Cause chemical changes in radiographic & photographic film * Can penetrate body * Can be absorbed or scattered in the body * Can produce secondary radiation * Can dam
What is the medically useful diagnostic range of x-ray energies? 30 to 150 kVp
In what year were x-rays discovered? 1895
What is the speed of light? 3 x 10 to the eighth or 186,000 mph.
In what year were some of the biologically damaging effects of x-rays discovered? 1898
X-rays were discovered in experiments dealing with: the conduction of high-voltage electricity through low-vacuum tubes
X-rays were discovered when they caused a barium platinocyanide-coated plate to: fluoresce
X-radiation is part of which spectrum? electromagnetic
X-rays have a dual nature, which means that they behave like both: waves and particles
How are the wavelength and frequency of x-rays related? inversely
Who won the 1st Nobel prize in physics in 1901? Wilhelm Conrad Roentgen
How fast does a rotating anode spin? 3,000 to 10,000 rpm
What is the atomic number of tungsten? 74
What is a mammography target made of? Molybdenum - atomic #42
Where to the majority of heat come from in x-ray production? the anode
What percent of the primary beam reaches the image receptor? 5%
The physical area of the target that is bombarded by electrons during x-ray production? Focal spot
The actual focal spot and effective focal spot are related: Directly
What is the advantage of a rotating anode verses a stationary anode? Rotating anode dissipates heat better
What is the acceptable leakage radiation? 100 mR per hr no more than 1 meter from the source
What is the Source-to-skin distance requirements? Shall not be less than 12 inches and should not be less than 15 inches
What percentage of interactions above 70kVp are Bremsstrahlung? 85%
What percentage of interactions below 70kVp are Bremsstrahlung? 100%
Produced when a projectile electron interacts with an electron from the inner shell (K-shell) of the tungsten atom Characteristic interactions
A German word meaning "braking" or "slowing down" Bremmstrahlung
True or False: There is no difference between a Bremsstrahlung interaction and a Characteristic interaction at the same energy level. True
What determines the speed at which the electrons in the tube current move? kVp
What is the unit used to measure the tube current? milliampere (mA)
Coiled tungsten wire that is the source of electrons during x-ray production filament
What is made up of nickel & nearly surrounds the filament? focusing cup
Allows electrons to flow freely across the tube from the cathode to the anode focusing cup
positively charged electrode anode
a metal that abruptly decelerates & stops electrons coming from the tube current, thereby allowing the production of x-rays target
What is the target of rotating anode tubes made of? Tungsten
Atomic # of tungsten 74
What is the melting point of tungsten? 3370 C
In mammography, what is the target made of? Molybdenum
Atomic # of molybdenum 42
What has a high melting point, but produces a much lower x-ray beam? Molybdenum
Number of waves passing a given point per given unit of time. Frequency
What is the difference between Bremstrahlung & Characteristic x-rays at the same energy level? There is no difference, they are just different processes.
What turns the rotor at a very high speed? stator
What rotates rapidly during x-ray production? rotor
The physical area of the target that is bombarded by electrons during x-ray production. focal spot
Any x-rays other than the primary beam that escape the tube housing. leakage radiation
In what direction do electrons travel? cathode to anode
How fast do electrons travel? half the speed of light
What 2 interactions produce x-ray photons? Bremsstrahlung & Characteristic
German word that means "breaking" or "slowing down" Bremsstrahlung
Focal spot size as measured directly under anode target Effective focal spot size
True or False: The amount of anode angle determines the size of the focal spot. True
Describes how x-ray intensity is greater on cathode side, with the intensity diminishing Anode heel effect
How is mAs calculated? mA x s milliamperage x seconds
Doesn't allow any more electrons to be boiled off the filament. space charge effect
What is the ejected electron in Compton effect called? compton electron or recoil electron
single-phase factor 1.0
The amount of heat produced from an exposure is expressed by the... heat unit
What factors do radiographers select to produce a quality image? * kilovoltage (kVp) * milliampere (mA) * exposure time
How is mAs calculated? mA x s milliamperage x seconds
Doesn't allow any more electrons to be boiled off the filament. space charge effect
What is the ejected electron in Compton effect called? compton electron or recoil electron
single-phase factor 1.0
The amount of heat produced from an exposure is expressed by the... heat unit
What factors do radiographers select to produce a quality image? * kilovoltage (kVp) * milliampere (mA) * exposure time
Allows imaging movement of internal structures. fluoroscopy
invisible until processed latent image
visible image manifest image
positively charged electrode anode
How are the quantity of electrons that flow from cathode to anode & the quantity of x-rays produced related to exposure time? they are directly proportional
The most important part of the x-ray machine because it is where x-rays are produced. x-ray tube
Describes how x-ray intensity is greater on cathode side, with the intensity diminishing toward the anode side. Anode heel effect
x-rays are also called photons
A radiographic image is created by passing an x-ray beam through the patient & interacting with the image receptor
True or False: At higher kilovoltages, fewer photon interactions occur, resulting in more x-ray transmissions. True
What percentage of electrons in the tube current is converted to heat? 99%
What kind of paper was Roentgen using when he discovered x-rays? barium platinocyanide
Absorption is similar to what interaction? Characteristic
negatively charged electrode cathode
focuses electrons electrostatic lenses
Flow of electrons from cathode to anode tube current
Process where some of the x-ray beam is absorbed in the tissue & some passes through the body Differential absorption
True or False: The more mA, the more x-rays produced True - they are directly related
How are wavelength and frequency related? inversely
Three types of x-ray generators: * Single-phase * Three-phase 6 pulse * Three-phase 12 pulse * High frequency
Type of double-wedge filter used for AP projection of the thorax trough filter
How fast is the speed of light? 3 * 10^8 meters per second 186,000 miles per second
X-ray tubes operating above 70 kVp must have a minimum total filtration of ______ or its equivalent 2.5 mm of aluminum
What percentage of electrons in the tube current are converted to x-rays? 1%
Type of double-wedge filter used for AP projection of the thorax trough filter
How fast is the speed of light? 3 * 10^8 meters per second 186,000 miles per second
X-ray tubes operating above 70 kVp must have a minimum total filtration of ______ or its equivalent 2.5 mm of aluminum
What percentage of electrons in the tube current are converted to x-rays? 1%
Incoming x-ray photon passes through the anatomic part without interactions transmission
What kind of relationship does the speed of electrons traveling from cathode to anode have with kilovoltage? direct relationship; speed of electrons increase as kilovoltage increases
Heat unit equation HU = mA * time * kVp * gen. factor
Boiling off of electrons from the filament thermiotic emission
What is made of nickel & nearly surrounds the filament? focusing cup
Coiled tungsten wire that is the source of electrons during x-ray production filament
Occurs with low energy x-rays; photon interacts with atom & excites it; the atom DOES NOT lose energy, but it does change direction Coherent scattering
cloud that forms around filament after thermiotic emission space charge
Three-phase 6 pulse factor 1.35
Three-phase 12 pulse 1.41
Filtration added to the port of the x-ray tube Added filtration
Most common type of compensating filter - thicker portion is lined up with thinner portion of body wedge filter
When the attenuated x-ray beam leaves the patient, the beam is called exit radiation
During this interaction, projectile electrons interacts with k-shell electron & produces a "cascading" effect which produces x-ray photons Characteristic interaction
What heats the tungsten filament? filament current
filtration permanently in the path of the x-ray inherent filtration
the amount of filtration that reduces the intensity of the x-ray to 1/2 its original value half-value layer
radiation that has both electrical & magnetic properties electromagnetic radiation
creates brighter image output phosphor
any x-rays other than the primary beam that escape the tube housing leakage radiation
tube current is measured in mA
Incoming photons are not absorbed, but they lose energy during interaction in the body scattering
When does complete absorption occur? when incoming x-ray photon has enough energy to remove the inner shell electron
Components that contribute to inherent filtration: * glass envelope * oil that surrounds tube * mirror inside collimator
can be added to the primary beam to alter intensity compensating filters
What is used to determine whether a particular exposure will be safe to make? instantaneous load tube rating chart
Bremsstrahlung Interaction electron avoids orbital electrons & get close to nucleus & changes directions
polyenergetic beam that consists of a wide range of energies x-ray emission spectrum
focal spot size as measured directly under anode target effective focal spot size
interactions that can occur within all diagnostic x-ray energies Compton interactions
allows electrons to flow freely across the tube from the cathode to the anode focusing cup
What exposure factors allow the x-ray beam to be altered? * quality * quantity
What do low energy photons do? Contribute to patient dose. They do NOT contribute to image formation.
radiation measuring device dosimeter
distance between two successive crests or troughs wavelength
The ejected electron resulting from total absorption of the photon during the photoelectric effect interaction. photoelectron
the ability of an x-ray photon to remove an electron ionization
In what year did they discover that x-rays could cause biological damage? 1898
converts light to electrons photocathode
What converts exit radiation photons to visible light in the image intensifier? input phosphor
Interaction where energy scatters and changes direction Compton effect
Process in which exit radiation from the area of interest interacts with light emitting material image intensification
What is x-ray energy measured in? kiloelectron volts (kev)
density on the x-ray is equal for any combination of mA & time as long as the product is equal mAs reciprocity
High frequency generator factor 1.45
Product of both flux/minification gain Brightness gain
When ionization occurs in the diagnostic range Photoelectric effect
What is exit radiation composed of? * transmitted radiation * scattered radiation
Added filtration and inherent filtration total filtration
What kind of tubes was Roentgen working with when he discovered x-rays? Crookes tubes
Reduction in the energy of the primary beam attenuation
refers to the instantaneous production of light resulting from the interaction of some type of energy & some element/compound fluorescence
What determines the length of time that the x-ray tube produces x-rays? exposure time
size of the area on the anode target that is exposed to electrons from the tube current actual focal spot
the relationship between the actual focal spot & the effective focal spot Line-focus principle
What relationship does kVp and penetrability have? Direct relationship: as kVp increases, penetrability increases
What is the device that receives the radiation that exits the patient to create the radiographic image? image receptor
What are some factors that affect the beam interaction? * quantity of primary beam * quality of primary beam * composition of the anatomic tissues
The process of image formation is a result of: differential absorption
What is the process whereby some of the x-ray beam is absorbed in the tissue and some passes through the anatomic part? differential absorption
What does the word "differential" mean? varying
Does differential absorption increase or decrease as kVp is reduced? increase
What are the processes that occur during beam attenuation? * absorption * scattering * transmission
The variations between _______ and __________ of the exiting x-ray beam will structurally represent the anatomic area of interest. absorption and transmission
The reduction in the energy of the primary beam is known as: attenuation
When absorption takes place, what is the ejected electron called? photoelectron
A total x-ray absorption interaction Photoelectric Effect or Photoelectric Interaction
Photoelectric interaction results in areas in the radiograph that are ____. This means that the resulting image will possess ______ density. light low
Probability of total photon absorption is dependent on: * the energy of the incoming x-ray photon * the composition of the anatomic tissue
What is the ability of an x-ray photon to remove an electron? ionization
The photoelectric effect if responsible for total ________ of the incoming x-ray photon. absorption
The energy of the incoming x-ray photon must be at least _____ to the binding energy of inner shell electrons. equal
True or False: The overall energy of the primary beam increases as it passes through the anatomic part. False
The process of ________ means that the photons lose energy and are not absorbed during interaction; instead, the photon changes direction. Compton scattering
_____ is an outer shell electron interaction. Compton effect
The electron that is ejected during the compton effect is called a compton electron or recoil electron
During the process of Compton scattering, the incident photon continues on an altered path, scattered, with less energy and a _____ wavelength than before the collision. longer
True or False: Scattered radiation contributes to radiation dose to the patient and provides useful information about the anatomic area of interest. False
The percentage of Photoelectric interactions _______ at a higher kilovoltage. decrease
The percentage of Compton interactions _______ at higher kilovoltage. increase
If the incoming x-ray photon passes through the anatomic part without any interaction with the same atomic structures, it is called: transmission
Transmission is more likely to occur with ________ kVp. high
The incoming x-ray photons that are transmitted create the _______ areas on the radiograph and the resulting image will produce _______ density. dark / high
True or False: The quality of the image created is compromised if the scattered x-ray photon strikes the image receptor. True
Radiation that leaves the patient is called: exit radiation
Exit radiation consists of ________ and ________ radiation. transmitted and scattered
Scatter radiation creates unwanted density on the image called: fog
What percentage of the primary x-ray beam actually reaches the image receptor? less than 5%
The x-ray beam that reaches the image receptor creates the ______ or invisible image. latent
Developing and processing an exposed film produces the _______ image. manifest
Anatomic tissues that vary in absorption and transmission create the ___________ on the image. range of densities
Imaging the movement of internal structures is known as: fluoroscopy
What is the process in which the exit radiation form the anatomic area of interest interacts with a light emitting material for conversion to visible light? image intensification
The light emitting material is called input phosphor
Which image intensifier component converts the visible light intensities from the input phosphor to electrons? photocathode
What is the purpose of electrostatic focusing lenses? to focus electrons into a narrow stream toward the output phosphor
The image light intensities from the output phosphor are converted to an __________ and sent to a TV monitor for viewing. electronic video signal
What are the 2 types of digital radiography that is commonly used today? CR - Computed radiography DR - Direct digital radiography
True or False: Regardless of whether the imaging is CR or DR, the computer can manipulate radiographic image in a variety of ways. True
In digital imaging, the latent image is stored as ________ and must be processed by computer for viewing. digital data
True or False: The process of differential absorption is different on each type of image receptor. False
Created by: kkant on 2010-09-21



bad sites Copyright ©2001-2014  StudyStack LLC   All rights reserved.