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53 Cards in this Set
- Front
- Back
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radiology
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Branch of medical science that deals with the use of radiant energy in the diagnosis and treatment of disease
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Rodiography
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the makeing of radiographs by exposing and processing xray film
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radiograph
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and image produced on photosensitive film by exposing the film to xray and then developing it
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radiation
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the emission and propagation of emergy through space or through a material medium in the form of electromagnetic waves,
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radiation field
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the region where the evergy is being propagated
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wilhelm konrad roentgen
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discover xradiation
exposed his wifes hand for 20 min! rings on finger were visable. won nobel prize in 1901 |
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otto walkoff DDS
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sopposedly exposed first dental radiograph
exposed his own mouth for 25 min. |
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dr C. Edmond Ells
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exposed first intraoral radiograph.
30 min exposure time. had cancer and many amputations commited suicide |
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Dr. William Herbert Rollins
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Father of modern radiation protection.
recodnized many of the dangers of xrays. |
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Nucleus
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possitive charge
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orbital electrons
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negative charge
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electron orbits
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in a normal atom there is a balance between centripetal foce and electrostatic force
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binding energy
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energy required to move and electron from its shell.
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Ionising Radiation
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when ions pairs are formed, chemical chances occur in matter;
when nutral atom gains or loses electron |
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Particulate corpuscular radiation
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minute particles of matter that travel in stright line at high speeds; they posses mass and are electrically charged
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electromagnetic radiation
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propagation of energy through space accompanied by electric and megnetic force fields
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X-Ray
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man-made and produced outside nucleus of stable atom
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wave concept
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wlectromagnetic radiaiton isi the propagation of wave like energy through space or mass at the speed of light
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wavelength
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distance between two crsts
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frequency
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# of waves passing a set point
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short wave length
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high frequency
high energy hard xray stronger |
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Particle concept
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electromag. radiation senn as bundles of energy called guanta of photons
used to descride the interaction between radiation and matter they have no mass travel at the speed of light and energy depends on frequency. |
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photons
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little bunbles of energy running into matter
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electromagnetic spectrum
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grouped acording to wavelengths
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scatter radiation
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diverges which means spreads out as it goes like a V
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Production of xrays
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the process of energy conversion
A.source of electrons B.Power the move electrons C.focusing of electrons D.torget to stop the electrons |
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Xray tube
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inside tubehead
sealed leaded glass envolope no air. contains to electrodes in a vacume Anode+ and cathode- |
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Cathode
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negative termanal
has tungsten wire (filaments)set in a cup |
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tungsten
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has a high melting point and is the source of electrons
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anode
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possitive termanal
must have a poss charge to attract electrons and is made of copper |
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target
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the block of tungsten set into the face of the copper anode
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focal spot
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area on target that electrons strike to generate xrays
the smaller the focal spot sharper the image |
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Generation of electrons
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the tungsten filament is the source of electrons it is heated to incandescents the oter shell electrons of the filament atoms escape via thermionic emission
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therminic emission
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the boiling off of electrons
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boiling of of electrons
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electron cloud
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temp. of filament
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controls the the quantity of electrons
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increas mA
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increase temo of the tugnsten filament
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voltage
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power or energy
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high circuit (KvP)
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causes the electons to accelerate to high speeds toward the target.
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high the voltage
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greater the speed the greater the speed more energetic of penetrating potons (more energy)
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cathode/molybdenum focusing cup
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casues the electron stream to converge on the focal spot
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focal spot
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is source of xray production
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stoping electrons
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high speed electrons hit focal spot on the tungsten target
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kinetic energy of the electrons is converted to
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99% head and 1% xrays
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Useful beam
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those 1% xrays leave threw the window of tube threw the BID
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kVp
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kilovoltage peak -maximum voltage across the tube causing aceleration of electrons
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keV
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kiloelectron volts-energy of an individual cathode electron in the beam
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Cathode electrons
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have a broad range of kinetic energy
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kenetic energy converts
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heat or radiation
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general/whate radiation
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bremsstrahlug or breaking radiaiton
most produced xrays in a dental unit interaction of a high speed cathode electron with a tunsten atom nucleus of the target anode+ |
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polyenergetic
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photons of varying wavelengeths and energies
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braking of cathode electrons vary
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so does energy of xray photons produced
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kvp varies
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so will kinetic energy
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