Final Flashcards
In what year were some of the biologically damaging effects of x-rays discovered?
1898
In what year were x-rays discovered?
1895 (Wilhelm Conrad Roentgen)
X-rays were discovered in experiments dealing w/ electricity & ___?
Vacuum tubes (Crooke’s tubes)
X-rays were discovered when they caused a barium platinocyanide plate to?
Fluoresce
X-radiation is part of the _____ spectrum?
Electromagnetic
X-rays have a dual nature, which means that they behave like both…
Waves & particles
The wavelength & frequency of x-rays are ____ related?
Inversely
X-rays have a(n) ____ electrical charge
No charge
X-rays have \_\_\_\_\_\_ A. no mass B. the same mass as electrons C. the same mass as protons D. the same mass as neutrons
A. No mass
The x-ray beam used in diagnostic radiography can be described as being ______
Polyenergetic
Which X-ray tube component serves as a source of electrons for x-ray productions?
Filament
Electrons interact with the ______ to produce x-rays & heat
Target
The cloud of electrons that forms before x-ray production is referred to as?
Space charge
The burning off of electrons at the cathode is referred to as?
Thermionic emission
Which primary exposure factor influences both the quantity & the quality of x-rays photons?
kVp
The unit used to express tube current is?
mA
What percentage of the kinetic energy is converted to heat when moving electrons strike the anode target?
99%
The intensity of the x-ray beam is greater on the ?
Cathode side of the tube
According to the line focus principle, as the target angle decreases, the ______?
Effective focal spot size decreases
____ will extend X-ray tube life
Warming up the tube after 2 hours of non-use
The process whereby a radiographic image is created by passing an x-ray beam through anatomical tissue is known as?
Differential absorption
Which of the following processes occurs during beam attenutation: 1) absorptions, 2) photon transmission, or 3) scattering?
1,2, & 3
The ability of an x-ray photon to remove an atom’s electron is a charac. known as?
Ionization
The x-ray interaction responsible for absorption is ?
Photoelectric
The x-ray interaction responsible for scattering is?
Compton
Exit radiation is composed of which of the following: 1) transmitted radiation, 2) absorbed radiation, or 3) scattered radiation?
1 & 3 only
What interaction creates unwanted density known as fog?
Compton
The low-density areas on a radiographic image are created by?
Absorbed radiation
An anatomic part that transmits the incoming x-ray photon will create an area of ___ on the radiographic image
High density
Development & processing of an exposed film will result in a(n)
Manifest image
A radiograph that needs no improvement is defined as?
Optimal
Factors that affect visibility of a radiographic image are known as?
Photographic
A radiograph that has insufficient density would best be described as?
Underexposed
Which of the following is equivalent to doubling the mAs?
increase the kVp by 15%
A radiograph was taken using 65kVp, 200mA at 0.10s. The image needs to be repeated b/c it is too dark. What exposure technique adjustment would be best?
65kVp, 200mA at 0.05s
What is the relationship b/w milliamperage & exposure time to maintain density?
Inverse
When repeating a radiograph to correct for a density error, it is recommended to adjust the mAs by a factor of?
2
Which of the following when decreased will increase density: 1) grid ratio, 2) focal spot, or 3) part thickness?
1 & 3 only
How will radiographic density be affected when the SID is decreased by half?
Increased
A radiographic image described as having too many shades of gray would be?
Low contrast
The visible differences b/w adjacent radiographic densities defines
Contrast
Which of the following will increase radiographic contrast?
Increasing the grid ratio
Radiographic contrast can be increased by
Adding contrast media
What factor has the most direct effect on radiographic contrast?
kVp