test 1-3 Flashcards
atoms and molecules are the fundamental building blocks of
matter
the formula e=mc2 represents
nuclear power
ionizing radiation is capable of _____ electrons
removing
biggest source of man made radiation
diagnostic x-rays
exposure is measured in
grays
today radiology is considered
a very safe operation
ALARA means
As low as reasonably achievable
filtration is used to absorb
low energy x-rays
photons with the highest frequencies have the
shortest wavelength
which scientist discovered x-rays
william roentgen
crookes
smallest particle all the properties of an element
atom
positively charges nucleus surrounded by negatively charged electrons is what theory?
Bohr
atom is normal state is
electrical charge is 0
binding energies is represented by
shells
atom same number proton but different number neutrons is called
isotope
atoms combines form is called
molecules
atom looses or gains electrons
ion
innermost electron shell is
K
a chemical compound is any quantity of
one type of molecule
during beta atom releases
electron
the only difference between gamma and x-ray is their..
origin
smallest electromagnetic radiation
photon
rise and fall of sin wave is
frequency
wavelength beam of electromagnetic radiation is increases by factor of 2 then frequency is
decreased by half
the reduction of radiation intensity due to scattering and absorption is called
attenuation
the lowest energy range of electromagnetic spectrum is
radio waves
photons tend to interact with matter
equal in size with their wavelengths
smallest unit of charge is
electron
like charges _____ unlike charges ____
repel, attract
on the surface of an electrified object the charges concentrate on
the sharpest curvature
a ____ is a source of direct current
battery
ohms law
i=v/r
rubber and glass are
insulators
the magnetic intensity of an electro magnets is greatly increased by the addition of a
iron core
an alternating ac current is represented by
sinusoidal line
US alternating current goes through a complete cycle every
1/60 seconds
test 2 \_\_\_\_\_\_\_\_\_ is defined as the ability to image two separate objects and visually detect one from the other. Contrast Resolution Detail Noise
resolution
Higher speed image receptors generally produce images with \_\_\_\_\_\_\_\_\_\_\_\_. better resolution increased noise higher contrast improved detail
increased noise
In general radiography, the useful optical densities lie between _____ and _____.
- 25, 2.5
- 5, 1.0
- 0, 1.5
- 0, 3.0
0.25,2.5
The best way to minimize magnification is to use a \_\_\_\_\_\_\_\_\_\_. long SID small OID large OID Both A and B
both A and B
Distortion can be reduced by ____________________________.
placing the object plane perpendicular to the image plane
placing the object plane parallel to the image plane
directing the central ray 15° from the object plane
increasing the SID and the OID
placing the object plane perpendicular to the image plane
The \_\_\_\_\_ represents zero or one. byte bit gigabyte terabyte
bit
In computer language, \_\_\_\_\_\_\_\_\_ is a “word.” 2 bytes 2 bits 16 units 8 pixels
2 bytes
Projectile electrons travel from \_\_\_\_\_\_\_\_\_\_\_\_\_\_. anode to cathode cathode to anode target to patient inner shell to outer shell
cathode to anode
During an exposure, most of the \_\_\_\_\_\_\_\_ energy of the projectile electrons is converted to \_\_\_\_\_\_\_\_ kinetic, x-rays x-ray, kinetic kinetic, heat heat, kinetic
kinetic, heat
The efficiency of x-ray production is ___________ the tube current.
indirectly proportional to
directly proportional to
not affected by
strongly affected by
not affected by
Electron interactions at the inner-shell of the target atoms produce _____ radiation.
gamma
Bremsstrahlung
characteristic
all of the above kinds of
characteristic
Characteristic x-rays are produced by __________________.
braking electrons
excitation of outer shell electrons
nuclear fragmentation
released binding energy
released binding energy
The quantity of bremsstrahlung radiation increases proportionately with increased _____.
kVp
mAs
filtration
rotor speed
mAs
The ______________ of an x-ray beam is higher when the peak of the emission spectrum is further to the __________.
quality, right
quantity, right
quality, left
quantity, left
quality right
number of x-rays in the useful beam defines x-ray ________.
kVp
quality
quantity
mAs
quantity
X-ray quantity increases in direct proportion to increases in __________.
mAs
kVp
distance
filtration
mAs
If the distance from the source to the image (SID) is reduced by half, how is the x-ray intensity at the image affected?
It is increased 4 times.
it is doubled.
It is reduced by 1/2.
It is reduced by 1/4.
increased 4 times
Beam quality is affected by ______________.
mAs and distance
kVp and mAs
kVp and filtration
filtration and mAs
kVp and filtration
-ray beam quality is improved by ____________.
lowering kVp
decreasing filtration
increasing filtration
increasing distance
increasing filtration
The two primary forms of x-ray interaction in the diagnostic range are ________________.
Compton scattering and photoelectric absorption
Compton scattering and pair production
photoelectric absorption and coherent scattering
coherent scattering and Thompson scattering
Compton scattering and photoelectric absorption
An incident x-ray interacts with an atom without ionization during \_\_\_\_\_\_\_\_\_\_\_\_\_\_. photoelectric absorption Compton scattering coherent scattering pair production
coherent scattering
Which x-ray interaction involves the ejection of the K-shell electron?
Coherent scattering
Compton interaction
Pair production
Photoelectric absorption
photoelectric absorption
Compton scatter is directed at _____ angle from the incident beam.
a 180°
a 90°
a 0°
any
any
In ________________, there is complete absorption of the incident x-ray photon.
photoelectric interaction
Compton interaction
pair production
coherent scatter
photoelectric interaction
___________ occurs only at the very high energies used in radiation therapy and in nuclear medicine P.E.T. imaging.
Coherent scatter
Compton scatter
Photoelectric absorption
Pair production
pair production
K-shell binding energy increases with increasing ____________.
mass density
kVp
atomic number
mAs
atomic number
Which has the greatest mass density?
Fat
Soft tissue
Bone
Air
Bone
Barium is a good contrast agent because of its __________________.
low atomic number
high atomic number
light color
low density
high atomic number
Computed radiography screens respond to radiation with ______________________.
fluorescence
electron emission
photostimulable luminescence
biological phosphorescence
photostimbulable luminescence
The computed radiography cassette is called a(n) ______________ plate.
optical
imaging
laser
thermoluminescent
imaging
The principal source of noise in computed radiography is ____________________.
scatter radiation
background radiation
computer noise
phosphor scatter
scatter radiation
The digital imaging plate can sit for some time after the erase cycle.
True
False
false
