radiographic Imaging
raw image contrast
Quantum or particle of radiant energy
photon
radiation resulting after the xray beam exits the object
Remnant radiation
true edge of an object as imaged radiographically
Umbra
series of picture elements or detector elements arranged in rows and columns
Matrix
Picture element and the smallest component of the matrix
pixel
radiation produced from xray photon interactions with matter in such a way that the resulting photons have continued in a different direction
Scatter radiation
Measurement of milliamperage multiplied by the exposure time ins seconds, which controls the total quantity of Xray photons produced in the xray tube.
Milliampere-seconds (mAs)
xray beam after it leaves the xray or other forms of radiant energy with the little attenuation
Primary radiation
distance between the source of the xrays (usually the focal spot of the xray tube) and the image recepetor
source-to-image distance (SID)
ability of an xray beam to pass through an object, controlled by the kilovoltage peak of the beam
penetrating ability
Permitting the passage of xrays or other forms of radiant energy with little attenuation
radiolucent
degree of accuracy of the structural lines actually recorded in the image
spatial resolution
ALARA
Term for Radiation Protection
As Low As Reasonably Achievable
fuzzy edge of an object as imaged radiographically: also known as image sharpness
Penumbra
Not easily penetrable by xrays or other forms of radiant energy
radiopaque
Range of differences in the intensity of the xray beam after it has been attenuated by the subject
subject contrast
Image Production: How are x-rays produced and how do they form on cassettes/image plates/image receptors?
An Xray is electro magnetic radiation in short wavelengths that are produced when electrons moving at high velocity are suddenly stopped.
Image production:
1. beam of Xray produced by passing high voltage through cathode tube.
2. moves through patient, partially absorbed.
3.Image receptor intercepts Xray protons that are able to exit patient.