On what date were x-rays discovered?
November 8, 1895
Who discovered x-rays?
Wilhelm Conrad Roentgen
How long was the first exposure, and what was demonstrated?
15 minutes, Hand
What is defined as radiation that has both electrical and magnetic properties?
Electromagnetic Radiation
What is represented by the distance between two successive crest or troughs?
wavelength
The energy of individual photons is measured in what?
electron volts
Air kerma is the amount of energy deposited in air, how is it expressed?
Gray
What does c represent in the formula C=?v?
speed of light
Speed of light is represented by 3x10^8, how manny miles/s is the light traveling?
186,000
What units are used to measure occupational exposure?
REM and SV
What is the cathode comprised of?
Filament and focusing cup
What is the focusing cup made of?
Nickel
The filament would be described as a ___________, which serves as source of electrons during x-ray production?
coiled tungsten wire
True or False, Tungsten has a melting point of 3400�C.
True
What is defined as x-rays, other than the primary beam, that escape the tube housing?
leakage radiation
What does bremsstrahlung mean?
Breaking radiation
Leakage radiation is not allowed to acceded what amount?
100mR/hr
What is the diagnostic energy range?
30-150kVp
What is the filament current range?
3-5 ampers
The x-ray beam has what energy?
polyenergetic
How is tube current measured?
Milliamperes
How much percent of the kinetic energy is converted to x-rays as electrons strike the anode target?
1%
As kVp increases, beam penetrability does what?
increases
How is mAs mathematically expressed?
mAxS =mAs
How much total filtration in the x-ray beam?
2.5 mm of aluminum of equivalent
What is the device that receives radiation leaving the patient?
image receptor (IR)
The process of image formation is the result of what of the x-ray. beam as it interacts with anatomic tissue?
differential absorption
What is the reduction in the intensity or number of photons in the primary x-ray beam?
attenuation
Coherent interaction occurs with high or low energy x-rays?
low
In the Compton effect the ejected electron is known as what?
Compton electron or secondary electron
What interaction causes unwanted exposure to the image, known as fog?
Compton
The x-ray interaction responsible for absorption is what?
photoelectric
Visibility of the recorded details is achieved by the proper balance of what?
image brightness and contrast
What is the range of exposure intensities an image receptor can accurately detect?
dynamic range
Quantum noise is what dependent?
photon
Shape distortion can appear what two ways?
elongation and foreshortening
Size distortion (magnification) are controlled by what two factors?
OID and SID
What is referred to as the smallest object that can be detected in an image?
spatial resolution
High contrast is also known as what?
short-scale contrast
What is used to describe the ability of an imaging receptor to distinguish between object having similar subject contrast?
contrast resolution
What is the number of bits that affects the number of shades of gray available for image display?
Pixel bit depth
Extreme exposure is also called what?
saturation
pixel size=
FOV/matrix
What is used to evaluate the accuracy of the anatomical structural lines?
spatial resolution
When you widen the widow what contrast is displayed?
the image has lower contrast
When the signal is increased, what does patient dose do?
increase
What is the amount of luminescence on a display monitor?
brightness
What provides a numeric value indicating the level of radiation exposure to the IR?
Exposure indicator (EI)
what is the measure of the imaging systems ability to display the contrast of anatomic objects varying in size and the value will be between 0 and 1.0?
Modulation transfer function (MTF)
How is the number of pixels in one area represented?
Pixel density
With a greater number of pixels per unit area, what happens in regards to spatial resolution?
improved spatial resolution
What does a line pair consist of?
A line and a space
True or False; does a imaging system have 100% conversion efficiency?
False
Some information is always_________ during the process of image formation?
always lost
Double exposing an image will likely result in what?
image artifact