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xray DH

Making radiographs by exposing an image receptor,by film or digital sensor radiography
Study of x-rays and techniques to produce radiographic images oral radiology
An image or picture produced by x-rays a) picture b) radiograph c) total graph d) digital picture b) radiograph
The study of x-radiation a) radiology b) radiography c) roentegen a) radiology
discovered x-rays? a) Francis Mouyen b) H. R. Raper c) W.C. Roentegen c) W.C. Roentgen
wrote the first dental book? a) O. Walkhoff b) W. Roentegen c) H.R. Raper d) W. Coolidge c) H. R. Raper
When were x- rays discovered? 1895
older term given to x-radiation in honor of discoverer? roentgen ray
Term used by oral health care professionals, more descriptive than x-ray & easier to pronounce radiograph
Introduced Victor CDX shockproof dental x-ray machine William David Coolidge & General Electric
Published "X Light Kills" warning of x-ray dangers W.H. Rollins
Unit capable of exposing entire dentition and surrounding structures on single image Panoramic radiography "pano"
Imaging system that allow for enhanced two and three dimensional images for diagnosis and treatment of dental conditions digital imaging
Method of imaging a single selected plane of tissues, used to assist dentists with complex diagnosis and treatment planning computed tomography "CT scans"
Who exposed prototype of first dental x-ray film Otto Walkhoff
imaging system most likely to become gold standard for imaging certain dental conditions in near future cone beam volumetric tomography
given credit for applying rule of isometry to bisecting technique A. Cieszynski
given credit for developing paralleling technique Franklin McCormack
Currently we know of __________ basic elements 118
Each element made up of __________ atoms
smallest particles of element, retains properties of element atom
smallest particle of substance, retains properties of substance molecule
__________ have negative charge and constantly in motion orbiting nucleus electron
has positive charge protons
has no charge neutrons
The number of protons in nucleus of an element determines ______________ atomic number
Electrons are maintained in their orbits by positive attraction of the protons, known as ________ binding energy
Atoms that gained or lost electrons are electrically unstable ions *ion is defined as a charged particle*
positively charged atom ion and negatively charged electron ion are called ion pair
Formation of ion pairs ionization
emission and movement of energy through space in form of electromagnetic waves radiation
radiation that produces ions ionizing radiation
process that certain unstable elements undergo spontaneous disintegration, result in new isotope radio activity
Dental x-rays do/do not involve use of radio activity do not
movement of wave like energy through space as combination of electric and magnetic fields electromagnetic radiation
Consists of orderly arrangement of all known radiant energies electromagnetic spectrum
Bundles of energy, travel through space at the speed of light, "bullets of energy" photons
Distance between two similar points on two successive waves Wave length *measured in angstrom (A) units*
Measurement, number of waves that pass given point per unit of time frequency * measured in hertz (Hz) *
speed of wave velocity
Long wave length -low frequency -low energy -less penetrating x-ray Soft radiation "Grenz rays"
Short wave length -high frequency -high energy -more penetrating power hard radiation
X-rays have following properties: -invisible -travel straight lines -travel speed of light - no mass or weight -have no charge -interact with matter causing ionization -penetrate opaque tissues and structures -affect biological tissue -affect photographic film
Dense structures, like bone and enamel appear white or gray on x-ray, this is called radiopaque * white *
Less dense structures, like pulp chamber, muscles and skin appear _____________ radiolucent * darker/gray *
bodies in motion, believed to be kinetic energy
___________ is produced when bombarding electron from tube filament collides with orbiting K electron of tungsten target Characteristic radiation
Produced when high-speed electrons are stopped or slowed down by tungsten atoms of dental x-ray tube general/bremsstrahlung
beam of x-rays passing through matter, weakened and gradually disappears, disappearance is called absorption
When x-ray passes through atom unchanged, no interaction occurs, this is called No interaction * 9% in dental radiology *
When low energy x-ray passes near atom's outer electron, may be scattered without loss of energy is called Coherent scattering (unmodified scattering, "Thompson scattering"
"All or nothing energy loss" X-ray imparts all energy to an orbital electron of some atom Photo electric effect
Similar to Photoelectric effect, only part of dental x-ray energy is transferred to electron, and new, weaker x-ray is formed and scattered in new direction Compton effect aka Compton Scattering
most widely accepted terms used for radiation units of measurement come from Systeme Internationale "modern version of metric system"
Amount of energy deposited, any form of matter (such as teeth, soft tissues, treatment chair) by any type of radiation (alpha, beta particles, gamma or x-rays) Absorbed dose
Unit for measuring absorbed dose gray (Gy) or rad
Term used for radiation protection purposes to compare biological effects of various types of radiation dose equivalent
unit for measuring, dose equivalent is sievert (Sv) or rem
aid in making more accurate comparisons between different radiographic exposures __________ is used to compare risk of radiation exposure a biological response effective dose equivalent
ionizing radiation, always present in environment background radiation
Contains regulating devices on dental x-ray machine control panel
enables tube head to be positioned on dental x-ray machine extension arm or bracket
contains x-ray tube that x-rays are generated tube head
5 major controls operated or will be preset on dental x-ray machine -line switch to electrical outlet -milliampere selector -kilovoltage selector -the timer -exposure button
measures amount of current passing through wires of circuit milliampere (mA selector)
determines available number of free electrons at cathode filament, therefore amount of x-rays that will be produced amperage
measures difference in potential or voltage across x-ray tube kilo volt peak (kVp) selector
Determines speed of electrons traveling toward target on anode, the penetrating ability of x-rays produced kVp
Flows continuously in one direction direct current (DC)
"The house hold current" changes direction of flow 60 times per second AC alternating current
Electromagnetic device for changing current coming into dental x-ray machine transformer
decreases voltage from wall outlet to approximately 5v, enough to heat filament & form electron cloud step-down transformer
increases voltage from wall outlet to approximately 60-100 kVp to propel electrons toward target step-up transformer
located in control panel, is voltage compensator that corrects minor fluctuations in current flowing through wires auto transfomer
measurement of number of electrons moving through wire conductor amperage
describes electrical pressure (difference in potential) between two electrical charges voltage
located inside tube head, a glass bulb from where air has been pumped to create vacuum x-ray tube
beam of x-rays, originates at focal spot and emerges through port of tube head primary beam or useful beam
x-ray in center of primary beam central beam
x-ray beam that is composed of variety energy wavelengths polychromatic
What metal is used for target in x-ray tube tungsten
Charged negatively during time that x-ray tube is operating to produce x-rays cathode
describes opening in tube housing, allows primary beam to exit port
removes low-energy, long wavelength energy from beam filter
process of heating cathode wire filament until red hot and electrons boil off thermionic emission
Three basic requirements for acceptable diagnostic radiograph -must be imaged as close to their natural shapes and sizes as the patient's oral anatomy will permit -area examined must be imaged completely -free of errors and show proper density, contrast, and definition
refers to portion of image that is dark or black, permit passage of x-rays with little or no resistance radiolucent * abscess, soft tissues, air space *
refers to portion of image that is light or white, areas are dense and absorb or resist the passage of x-rays radiopaque * enamel, dentin, bone *
degree of darkness or image blackening density
refers to many shades of gray that separate dark and light areas contrast
describes radiograph when density differences between adjacent areas are large -high contrast short-scale contrast
describes radiograph when density differences between adjacent areas are small - low contrast long-scale contrast
refers to detail and clarity of outline of structures shown on radiograph sharpness/definition
partial shadow around objects of interest penumbra
rules for casting a shadow image 1)small focal spot 2)long target-object distance 3)short object-image receptor distance 4)parallel relationship between object and image receptor 5)perpendicular relationship between the central ray of the x-ray beam & both the object & the image rece
to reduce size of penumbra resulting in sharper image and slightly less magnification small focal spot
to reduce penumbra and magnification long target-object distance
to reduce penumbra and magnification short object-image receptor distance
to prevent distortion of image parallel relationship between object and image receptor
to prevent distortion of image perpendicular relationship between the central ray of the x-ray beam and both the object and the image receptor
factors affecting radiographic image subject kilovoltage peak (kVp) scatter radiation film/digital sensor type exposure processing
small focal spot increase sharpness
large focal spot decrease sharpness
long target-image receptor distance increase image
short target-image receptor distance decrease sharpness
underexposed or over exposed radiograph will result in diminished or poor contrast
small part on target where bombarding electrons are converted into x-rays focal spot
when long PID is used, x-rays in center of beam are more parallel, resulting in less image magnification
object-image receptor distance should be kept to a minimum
result of unequal magnification of different parts of same object (image receptor is not parallel to object) distortion
increasing mA, increases (darkens) ___________ of radiograph density
decreasing mA, decreases (lightens) _________ of radiograph density
interval that x-ray machine is fully activated and x-rays are produced exposure time
increase mA, makes image density darker
decrease mA, makes image density lighter
increase time makes image density darker
decrease time, makes image density lighter
increase kVp, makes image density darker
decrease kVp, makes image density lighter
length of target-surface distance depends on length of position indicating device (PID)
quality of radiographic image improves whenever target-image receptor distance is increased
Increasing target-image receptor distance reduces fuzzy outline (penumbra), seen around radiographic images true
positioning image receptor far enough from teeth to enable it to be held parallel and using long 12in PID will increase quality of image definition true
degree of darkening of radiographic image is referred to as density
image contrast, not affected by milliamperage
fuzzy shadow around outline of radiographic image penumbra
distortion results when object and image receptor are not parallel
theory that x-ray photons collide with important cell chemicals and break them apart by ionization, causing critical damage to large molecules direct theory
theory based on assumption that radiation can cause chemical damage to cells by ionizing water within it indirect theory
term used to describe degree of susceptibility of various cells and body tissues to radiation radiosensitive
Which cell is most sensitive to damage from radiation white blood cells (lymphocytes)
all cells of body, except reproductive cells somatic cells
effect that occurs when biological change or damage occurs in irradiated individual, but not passed along to offspring somatic effect
describes changes in hereditary material that do not manifest in irradiated individual, but in future generation genetic effect
genetic cells eggs and sperm
radiation that depends on type, energy, and duration of radiation (greater of dose, more severe probable biological effect total dose
rate which radiation is administered or absorbed is very important in determination of what effects will occur dose rate
various species have wide range of radiosensitivity variation in species
lethal dose (LD) for each species is expressed in statistical terms. For humans LD is LD 50/30, estimated to be 4.5 gray (Gy) or 450 rad
younger, more rapidly dividing cells are more radiosensitive than older, mature cells, so children are more susceptible to injury than adults from an equal dose of radiation true
following initial radiation exposure, and before first detectable effect occurs, a lag time called latent period
following latent period, certain effects can be observed this is called period of injury
following exposure to radiation, some recovery can take place recovery period
certain amount of damage where there is no recovery occurs is called irreparable injury
when biological response is based on probability of occurrence rather than severity of change is called stochastic effect "all or nothing effect"
likelihood of injury or death from some hazard risk
primary cause of biological damage from radiation is ionization
direct injury from radiation occurs when x-ray photons strike critical cell molecules
indirect injury from radiation occurs when x-ray photons ionize water and form toxins
Which cell are most radio resistant muscle cells
dose response curve indicating that any amount of radiation, no matter how small, has potential to cause biological response is called nonthreshold
ALARA as low as reasonably achievable
what is considered short term outcome following radiation exposure acute radiation syndrome
comparisons between dental radiation exposures and natural background exposure effective dose equivalent
controls size and shape of useful beam collimation
collimation reduces scatter radiation
lead apron has to be made of at least .25mm lead or lead equivalent material
minimum total filtration that is required by x-ray machine that can operate in ranges above 70kVp 2.5 mm of aluminum equivalent
annual maximum permissible whole-body dose for oral health care personnel is 50 mSv
annual maximum permissible whole-body dose for the general public is 5.0 mSv
silver halide crystals are sensitive to radiation true
silver halide crystals, when exposed to x-rays, retains the latent image
When radiation reaches emulsion, silver halide crystals are ionized, or separated into silver and bromide and iodide ions that store energy as a latent image
_________ absorbs most radiation enamel
designed for use inside oral cavity intraoral films
_________ used to determine film orientation and used to distinguish between radiographs of patients right and left side identification dot
sizes of intraoral film 0, 1, 2, 3, 4
images coronal portions of both upper and lower teeth and crestal bone on same film bitewing radiographs
used to record detailed examination of entire tooth, from crown to root rip or apex periapical radiograph
ideal for recording large area of the maxilla, mandible, and floor of mouth occlusal radiograph
designed for outside of mouth extraoral films
large films, classified as screen film extraoral films
screen film means indirect exposure film
provides support for fragile film emulsion base
light and x-ray sensitive silver halide crystals
what is function of lead foil in film packet absorb backscatter radiation
What can be found on back side of intraoral film packet film speed number of films in packet embossed dot location
Which film has greatest sensitivity to radiation a) D- speed b) E- speed c) F- speed F- speed
size #4 intraoral film packet,most likely used to expose occlusal radiograph
What projection will dentist most likely prescribe for evaluation of specific tooth and surrounding structures periapical radiograph
Intensifying screens will reduce exposure time
What is considered to be a screen film panoramic
X-ray films should be stored away from heat and humidity
Role of this solution is to reduce exposed silver halide crystals within film emulsion to black metallic silver developer solution
Processing transforms________ image, which is produced when x-ray photons are absorbed by silver halide crystals in emulsion, into visible, stable image by means of chemicals latent
Basic steps of processing dental x-ray film are developing rinsing fixing washing drying
Removes unexposed and/or undeveloped silver halide crystals from the film emulsion fixer solution
Prevents rapid oxidation of developing agents preservative
Activates developing agents by providing required alkalinity activator
Restrains developing agents from developing unexposed silver halide crystals, which produce film fog restrainer
Slows the rate of oxidation and prevents deterioration of the fixing agent preservative
Shrinks and hardens the gelatin emulsion hardening agent
Stops further development by neutralizing the alkali of the developer acidifier
What is minimum distance from source of light and counter space where film will be handled 4 -ft
When film can be read under white light after 2-3 minutes of fixing is called wet reading
Manual processing can be used to produce a working radiograph without a darkroom in about ______ seconds 30
Process by which latent image becomes visible reduction
What is correct processing sequence develop, rinse, fix, wash, dry
The basic constituents of developer solution are developing agent (reducing agent) preservative activator restrainer
During which step of the processing procedure are the exposed solver halide crystals reduced to metallic silver developing
Which ingredient removes the unexposed/undeveloped silver halide crystals from the film emulsion sodium thiosulfate
Which ingredient causes emulsion to soften and swell activator
Which ingredient hardens emulsion potassium alum
Chemically, the developer used in automatic processor contains more _______ than developer used for manual processing hardener
Which colors of safelight filters is safe for processing all film speeds red
What is appearance of the radiographic image if film is exposed to safelight too long fogged
A thermometer is used for manual processing to determine temperature of developing solution
What is ideal temperature for processing film manually 68 F
Replenisher is addd to developing solution to compensate for oxidation loss of volume loss of solution strength
Which processing method requires most maintenance & strictest adherence to regular replenishment and cleaning automatic
Discrete units of information that together constitute an image pixel
The discernable separation of closely adjacent image details spacial resolution
Refers to number of paired lines visible in 1mm of an image line pair
Relating to mechanism in which data is represented by continuously variable physical quantities analog
Refers to total number of shades of gray visible in image gray scale
A ______ radiographic image exists as bits of information in computer file digital
The computer converts information into image that appears on computer monitor true
Digital radiography can be used for to detect caries to monitor an endodontic procedure to detect dental disease
When a transparency scanner or digital camera is used to convert an existing film-based radiograph to digital file, process is called digitization
The following are digital image receptors CCD CMOS PSP
Stores x-ray energy until later simulation by a laser beam, reads electric signal and converts it into digital image PSP (photostimuable phosphor plate)
smaller the number of pixels in image the sharper the spatial resolution true
Each pixel stores a number representing different shade of gray true
Digital radiography requires less radiation exposure to produce an image than film based radiography because the image receptor (CDC or CMOS) is more sensitive to x-rays than film
Image receptor is called a sensor
Polyester plate covered with phosphor crystals is called a photostimuable phosphor (PSP) plate
A solid state detector used in digital sensors. Converts x-rays to electrons that are sent to computer via a wire Charge-coupled device (CCD)
A solid state state integrated circuit used in digital radiography as an image receptor in the intraoral sensor Complementary metal oxide semiconductor (CMOS)
Digital imaging sensors that use rare earth phosphor coated plates. When exposed to x-rays, __________ stores the x-ray energy until stimulated by a laser beam to produce a digital image photostimuable phosphors (PSP)
Allows for comparison of digitally stored images to detect changes over time or prior to and after treatment interventions digital subtraction
To prevent transmission of disease among patients infection control
primary purpose of infection control is to prevent the transmission of infectious diseases
microorganism capable of causing disease pathogen
Agent used on living tissues to destroy or stop the growth of bacteria antiseptic
Absence of septic matter or freedom from infection asepsis
Soiling by contact or mixing contamination
Making someone immune to a disease immunization
Suspension of microorganisms that may be capable of causing disease produced during normal breathing and speaking microbial aerosol
Infection or presence of septic matter sepsis
practice of care to protect persons from pathogens spread via blood or any other body fluid, excretion or secretion standard precautions
total destruction of spores and disease-producing microorganisms, accomplished by autoclaving sterilize
Routes of infection are direct contact with pathogens direct contact with airborne contaminants present in aerosols indirect contact with contaminated objects or instruments
For infection to occur, four conditions must be present 1) a susceptible host 2) a disease causing microorganism 3)sufficient numbers of pathogen to initiate infection 4) an appropriate route (port of entry) to enter host
Use of chemical or physical procedure to reduce disease-producing microorganisms to acceptable level on inanimate objects disinfection
Chemical germicides inactivate spores, can be used to disinfect heat sensitive semicritical dental instruments high level disinfectant
Instruments used to penetrate soft tissue or bone critical instruments
Instruments that contact oral mucosa without penetrating soft tissue or bone semicritical instruments * x-ray image receptor holding devices
Clinical contact surfaces are those devices and surfaces of treatment area that may contact intact skin or may become contaminated by microbial aerosols or spatter, but not mucous membranes noncritical instruments * lead apron, PID, chin rest and head positioner
An approach to infection control that states that body fluids (except sweat) of all patients should be treated as if infected is standard precautions
What agency develops and provides recommendations for adoption of infection control guidelines, does not act as enforcer of these guidelines Centers for Disease Control and Prevention (CDC)
Spraying disinfectant directly on which of these should be avoided x-ray machine exposure switch
What should be done with image receptor immediately after removing it from patient's mouth remove excess saliva with a dry or disinfectant soaked paper towel
order of maintaining infection control after radiographic procedure remove patient treatment gloves remove lead apron put on utility gloves clean and disinfect
key to producing quality radiographic images is gaining patient trust presenting a confident, caring image communicating effectively
ability to share in patient's emotions and fellings is called empathy
Refers to relationship between patient and oral health care professional patient relations
Position assumed by body in connection with feeling or mood attitude
Used to communicate with others successfully interpersonal skills
Process by which information is exchanged between two or more patients communication
Effective use of words in ___________ begins with facing patient directly and maintaining eye contact verbal communication
Includes gestures, facial expressions, body movement, and listening non verbal communication
Consists of methods of exposing dental x-ray film, phosphor plates, or digital sensors within oral cavity intraoral
Examination that images coronal portions of teeth and alveolar crests of bone of both the maxilla and mandible on a single radiograph. Good for detecting carries Bitewing examination
Used to image apices of teeth and surrounding bone periapical examination periapical radiographs
Images entire maxillary or mandibular arch occlusal examination
_________ is technique of choice because is more likely to satisfy more of shadow casting requirements paralleling
Technique known as "rule of isometry" bisecting technique
________ technique is more likely to meet most of shadow casting rules, making technique less likely to produce image distortion Paralleling technique
Full mouth series consists of __________ films 18
procedure by which tube head and PID are aligned to obtain optimum angle at which radiation is to be directed toward image receptor is called angulation
____________ is changed by rotating tube head horizontally and vertically angulation
_________ is achieved by directing central rays perpendicularly toward surface of image receptor in horizontal plane horizontal angulation
Achieved by directing central rays perpendicularly toward surface of image receptor in vertical plane Vertical angulation
Vertical angulation is customarily described in degrees
When portion of image is not recorded on radiograph conecut error
Point of entry for central ray should be in middle for image receptor true
Holders designed to position phosphor plate or digital sensor film holders
How many size 2 image receptors are required by most health care practices for exposure of posterior radiographs of full mouth series 8
Anterior periapical image receptors are placed vertically/horizontally vertically
Posterior periapical image receptors are placed _________ in oral cavity horizontally
Where should embossed identification dot be positioned when taking periapical radiograph toward the incisal or occlusal edge of the tooth
Which setting would PID be pointing to the floor +20
What is correct seating position for patient during radiographic examination when an image receptor without an external aiming device is used occlusal plane parallel and midsaggital plane perpendicular to the floor
What is best sequencing for exposing full mouth series of periapical radiographs maxillary anteriors, mandibular anteriors, maxillary posteriors, mandibular posteriors
Advantage of using paralleling technique produces images with minimal dimensional distortion
Interproximal space is the embrasure
To compensate for increased object-image receptor distance needed to achieve parallelism, target-image receptor distance should be increased
Important reason for using a holder when utilizing paralleling technique is to stabilize image receptor in a position parallel to the teeth
Film holders designed for use with paralleling technique should have a long biteblock and L-shaped backing
Example of holder that can be used with both paralleling and bisecting techniques SUPA
Directing central rays perpendicular to plane of image receptor and perpendicular to long axes of the teeth describes which step of the paralleling technique vertical angulation
Cutting off root apex portion of image on a periapical radiograph results from inadequate vertical angulation
Results in incisal/occlusal edges being cut off image excessive vertical angulation
The __________ technique satisfies fewer shadow cast principles bisecting
__________ is applied when image receptor is not, or cannot, be placed parallel to long axes of the teeth bisecting
Tooth and film should be as close as possible bisecting technique
Imaginary line between two lines bisector
Image receptor holders designed for use with bisecting technique will most likely have a short/long bite block short
__________ is achieved by directing central ray of x-ray beam perpendicular to curvature of arch, through the contact points of these teeth horizontal angulation
Curvature of the arch mean tangent
When the vertical angulation is excessive foreshortened image
When the vertical angulation in inadequate elongated image
When utilizing bisecting technique, central ray of the x-ray beam is directed perpendicular to the bisector
Which of these target-image receptor distances is recommended for use with bisecting technique 8 in.
When utilizing bisecting technique, image receptor is placed as close as possible to the tooth
What term describes imaginary line between long axis of tooth and plane of image receptor bisector
Image receptor holders designed for use with bisecting technique should have a short biteblock and 105degree backing
What is suggested point of entry for directing central ray of x-ray beam when exposing maxillary incisors radiograph using bisecting technique tip of the nose
Radiation that may travel in direction opposite that of original x-ray. New x-ray may undergo another Compton scattering or it may be absorbed by photoelectric effect interaction secondary radiation
The sum of inherent and added filtration a) added filtrationt b) inherent filtration c) total filtration c) total filtration
Filtration built into machine by the manufacturer a) half value b) finished filtration c) secondary filtration d) inherent filtration d) inherent filtration
Placement of aluminum discs in path of x-ray beam between port seal of tube head and PID a) added filtration b) secondary filtration c) simple filtration a) added filtration
Beam filtration must comply with state and federal laws, safety requires an equivalent of _________ for x-ray machines operating in ranges below 70 kVp a) 2.5mm of aluminum b) .5mm of tin c) 1.5mm of aluminum d) 3.5mm of aluminum c) 1.5mm
X-ray machines operating over 70kVp require minimum of _________ of beam filtration to comply with state and federal laws a) 2.0mm aluminum b) 2.5mm aluminum c) 3.0 mm aluminum b) 2.5 aluminum
The ___________ of an x-ray beam is thickness (measured in mm) of aluminum that will reduce intensity of beam by one-half a) face value layer b) half-value layer c) the value of the layer b) half-valued layer
_________ controls size and shape of useful beam a) collimation b) collimator c) filtration a) collimation
________ is absorption of long wavelength, less penetrating, x-rays of polychromatic x-ray beam by passage of beam through sheet of material a) fusion b) filtration c) elimination b) filtration
Collimation reduces _______ a) exposure b) density c) beam strength d) scatter radiation d) scatter radiation
________ shape of collimator reduces size of x-ray beam and amount of scatter radiation (best to use) a) circular b) square c) rectangular c) rectangular
Created by: welchang