114 - Chapter 1-5 Review Questions Flashcards
In what year were X-rays discovered?
1895
In what year were some of the biologically damaging effects of x-rays discovered?
1898
X-rays were discovered in experiments dealing with electricity and _________?
Vacuum tubes
X-rays were discovered when they caused a barium platinocynaide-coated plate to ____________?
Fluoresce
X-radiation is classified in which spectrum?
Electromagnetic
X-rays have a dual nature, which means that they behave like both _______ and ________?
Waves and Particles
The wavelength and frequency of x-rays are ________ related?
Inversely
X-rays have _______ electrical charge
NO and or Neutral
X-rays have no ________?
Mass
The X-ray beam used in diagnostic radiography can be described as being________?
Polyenergetic
The unit that measures the transfer of radiation energy into tissue is known as the _________?
Gray
Which of the following will minimize radiation exposure to the patient?
a. beam restriction
b. gonadal shielding
c. screening for pregnancy
d. All of the above
All of the Above
Which x-ray tube component serves as a source of electrons for x-ray production?
Filament
Electrons interact with the________ to produce x-rays and heat.
Target
The cloud of electrons that forms before x-ray production is refereed to as?
Space Charge
The burning or boiling off of electrons at the cathode is referred to as ________?
Thermionic emission
Which primary exposure factor influences both the quantity and the quality of x-ray 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
_______ extends x-ray tube life.
Warming up the tube after 2 h of non-use
Which type of target interaction is responsible for most of the x-rays in the diagnostic beam
Bremsstrahlung Interactions
Increasing the kVp results in _______?
More x-rays and higher energy
Total filtration in the x-ray beam includes
inherent filtration and added filtration
The process whereby a radiographic image is created by variations in absorption and transmission of the exiting x-ray beam is known as?
Differential absorption
Which of the following processes occur during the x-ray beam interactions with tissue
Absorption
Photon Transmission
Scattering
The ability of an x-ray photon to remove an atoms electron is a characteristic known as?
Ionization
The x-ray interaction responsible for scattering is
Compton
Remnant radiation is composed of which of the following?
Transmitted
Scattered
What interactions causes unwanted exposure to the image, known as fog?
Compton
Which of the following factors would affect beam attenuation?
Tissue atomic number
Beam quality
The high brightness areas on a radiographic image are created by_______?
absorbed radiation
An atomic part that transmits the incoming x-ray photon would create an area of _______ on the radiographic image
Low brightness
True or False:
The process of creating a radiographic image by differential absorption varies for film- screen and digital imaging
False
Which attribute of a radiographic image affect the visibility of sharpness?
Contrast and brightness
A radiographic image with many shades of gray but few differences among them is said to have?
Low Contrast
Which of the following is defined as the range of exposure intensities that an image receptor can accurately detect?
Dynamic Range
Which of the following would improve digital image quality
Large matrix and increase pixel density
The type of image receptor that uses a photostimulable phosphor to acquire the latent image is __________
Computed radiography (CT)
Which of the following is used to extract the latent image from an imaging plate
Laser Beam
Which of the following will improve the quality of the digital image
Increased sampling frequency and decreased sampling pitch
Which of the following would improve the quality of the digital image for a given field of view (FOV)
A fixed matrix size and small imaging plate
What is the process of assigning a numerical value to represent a brightness value?
Quantization
Which of the following pixel bit depths would display a greater range of shades of gray is represent anatomic tissues
16 bit
Digital imaging system have a wide dynamic range
True
A lower signal to noise ratio improves the quality of digital image
False
Which of the following is a measurement of the efficiency of an image receptor in converting the x-ray exposure it receives to a quality radiographic
DQE
Which of the following is defined as a graphic representation of the pixel values
Histogram
What process is employed to maintain consistent digital image brightness for overexposure or under?
Automatic rescaling
Which of the following is NOT a numerical value indicating the level of radiation exposure to a digital image receptor?
a. sensitivity number
b. exposure indicator
c. window level
d. exposure index
Window level
What digital process alters image brightness and grayscale to improve the visibility of anatomic structures
lookup tables
What type of monitor passes light through liquid crystals to display a digital image
LCD
True of False:
Maintaining a low level of ambient lighting can improve soft-copy viewing of digital images
True
Display monitors used for soft-copy viewing of digital images should have _________?
High Luminance
Which of the following is NOT a function during post-processing of a displayed digital image
Automatic rescaling
A wider window width
Decreases contrast
What is the communication standard for information sharing between PACS and imaging modalities
DICOM
Which of the following is the latent image center for radiographic film
Sensitivity speck
Which of the following describes a film’s sensitivity to x-rays light
Speed
Intensifying screens are used to
Decrease patient exposure
The ability to emit light only when stimulated by x-rays is known as
Fluorescence
What term is defined as a measure of the amount of light transmitted through the film
Optical density
Change in radiation exposure have the greatest effect on optical densities in which sensitometric region?
Straight-line
Why is silver recovery necessary during film processing?
it is a natural resource
it is toxic to the environment
it has monetary value
When the exposure technique used produces densities outside the straight-line portion of a sensitometic curve, how was contrast affected?
Decreased