Radiology Terms Flashcards
Few shades of gray with high contrast is produced with ——KV p
Low Kvp
Radiograph with many light and dark areas ,but FEW shades of grey is said to have
High contrast
Film produce using 90 KVp and 0.25 seconds What exposure time is needed the same at 75 KVp
0.50 seconds
Increasing mA alone results in a film with
Increased density
The total energy contained in the X ray beam in a specific area at a given time is termed
Intensity
Increasing these will increase the intensity of the X-ray beam
KVp ,MA and exposure time
The HVL is the amount of
Aluminum needed to reduce the X-ray beam intensity by half
The KVy range for most dental X-rays is
More penetrating ability
Radiation produce with high KVp results in
Short wavelengths
Increasing MANY results in a increase in
Temp of filament and number of X-rays produced
The mA range dental radiography is
7to 15 mA
Thermionic emission occurs in the
Negative cathode
Which radiation accounts for 70%of all the X-ray’s energy produce at the anothe
General radiation
Primary radiation best describe as
Radiation exist the tubehead
Which type of scatter happens most often with dental X-rays
Compton
Why is an increased target film distance required in the paralleling technique
To avoid image magnification
Thin transparent coating that is placed over the emulsion
Proctetive layer
Chemical compounds that change when is exposed to radiation or light are termed
Halides crystals
Invisible pattern of stored energy on the exposed energy on the exposed film is termed
Late te image
Purpose of a lead foil sheet in the film packet is
To protect film from back scattered radiation
The —–the cristals ,the——the film speed
The large the cristal the film spread
Examined
Film position -parallel to the long axis vertical angulation -CR directed perpendicular to film /horizontal angulation -CR directed thru contact -open /film exposure -center X-rays beam to espose film
Molecule
2 or more atoms joined by chimical bonds
Ionization
Losing or gaining an electron
Radiation
Emission or propagation of energy though space or matter ,waves or particles
Ionizing
Radiation that is capable of producing ions by removing or adding electron to an atom
Velocity
Wave speed =speed of light
Wavelength
Distance b/t crest -energy and penetrating power
Frecuency
of wavelenths tha pass a giving points in a certain amount of time Low freq./long wavelength= increase energy
X-radiation
Type of high energy ,ionizing electromagnetic radiation
Amperage (mA)
of electron moving through the cathode to the anode
Voltage (KV)
Controls the current passing from the cathode to the anode
Speed of light
186.000 miles /seconds
Produce when radiation strikes matter, reduces penetrating power
Secondary radiation
When radiation is deflected off
Scatter radiation
What regulate the flow of electrical current to the filament of the X-ray tube
Low- voltage circuit
What is used to increase the voltage in the high - voltage circuit
Set- up transforme
Process by which unstable atoms undergo a spontaneous des integration in a effort to attain a more balance nuclear state (undergo decay trying to become more balance
Radioactivity
Who introduce paralleling tech . And expose first dental radiograph in the USA use live person
C.edmund Kells 1896
Introduce bisecting technique
Weston price 1904
Introduce bite - wing tech
Howard raper 1925
For components of a film packaging
X-ray film paper film wrapper lead foil sheet outer packaging
Tha higher the speed on the film
The faster the film expose and the less radiation to pacient ALARA
Four basic components of X-ray film
Film base adhesive layer film emulsion protective layer
Developer
Softens emulsion reduce exposed crystal to black metallic silver
Fixer
Hardens emulsion cleans away unexposed crystal silver halide
Chemical components that change when expose to radiation or light are termed
Silver halide crystal - reduce to black metallic silver
Five rules for paralleling tech
Film placement - most cover teeth to be
Compton scatter
62% X-ray photon is deflected form path during passage through matter (ionization occurs )
Coherent scatter
8% X-ray photon that has its path altered by matter no change in atom occurs , no ionization
