Ch. 8 Image Production Flashcards
the x-ray photons removed from the x-ray beam as a result of the uptake of their energy by body tissues
absorption
reduction in the energy or number of photons in the primary x-ray beam after it interacts with anatomic tissue
attenuation
an interaction that occurs with low-energy x-rays, typically below the diagnostic range. The incoming photon interacts with the atom, causing it to become excited. The x-ray does not lose energy but changes direction
coherent scattering
scattering that results from the loss of some energy of the incoming photon when it ejects an outer-shell electron from a tissue atom
Compton effect
the electron ejected from an atom during a Compton scattering event
Compton electron
used to describe the ability of the imaging system to distinguish between small objects that attenuate the x-ray beam similarly in digital imaging
contrast resolution
the difference between the x-ray photons that are absorbed photoelectrically versus those that penetrate the body
differential absorption
the range of exposure intensities that an image receptor can respond to and acquire image data
dynamic range
the attenuated x-ray beam leaves the patient and is composed of both transmitted and scattered radiation; also called remnant radiation
exit radiation
the use of a continuous beam of x-rays to create dynamic images of internal structures that can be viewed on a display monitor
fluoroscopy
unwanted exposure on the radiographic image that does not provide any diagnostic information
fog
a device that receives the radiation leaving the patient
image receptor
the removal of an electron from an atom
ionization
the invisible image that exists on the image receptor before it has been processed
latent image
the visible radiographic image on the exposed detector after processing
manifest image
combination of rows and columns (array) of pixels that make up a digital image
matrix
in the diagnostic range, the total absorption of the incident photon by ejecting an inner-shell electron of a tissue atom
photoelectric effect
the electron ejected from an atom during a photoelectric interaction
photoelectron
picture element; the smallest component of the matric, which is represented as a single brightness level on a computer monitor
pixel
also called number of bits, it affects the number of shades of gray available for image display
pixel bit depth
the attenuated x-ray beam leaving the patient that is composed of both transmitted and scattered radiation; also called exit radiation
remnant radiation
incoming photons are not absorbed but instead lose energy during interactions with the atoms composing the tissue
scattering
the ejected electron resulting from the Compton effect interaction; also called Compton electron
secondary electron
matter per unit volume, or the compactness of the atomic particles composing the anatomic part
tissue density
x-ray photons that pass through the body to expose the image receptor
transmission
occurs when the primary x-ray beam loses energy as it interacts with anatomic tissues
attenuation
what is beam attenuation affected by
- tissue thickness
- atomic number
- tissue density
- x-ray beam quality
x-rays can eject electrons from atoms within anatomic tissue called
ionization
3 primary processes that occur during x-ray interaction with anatomic tissues
- absorption
- transmission
- scattering
total absorption of the incoming x-ray photon is a result of what
photoelectric effect
scattering of the incoming x-ray photon is a result of what
Compton effect
this determines the available shades of gray to display the digital image or its contrast resolution
pixel bit depth
what type of dynamic range do digital IRs have
wide dynamic range
what type of dynamic range do film-screen IRs have
limited dynamic range
this allows imaging of the movement of internal structure for viewing on a display monitor
fluoroscopy
what describes the process of radiographic image formation
differential absorption
the range of exposure intensities an image receptor can accurately detect defines what
dynamic range
what will increasing the pixel bit depth do
increase contrast resolution
what type of imaging system uses an intensifying screen to convert x-rays to visible light
film-screen
