Chapter 7 Flashcards
Penetrating ability
Ability of an x-ray beam to pass through an object; controlled by the kilovolt peak of the beam
Penumbra
Fuzzy edge of an object as imaged radiographically; also known as image unsharpness
Photon
Quantum or particle of radiant energy
Primary radiation
X-ray beam after it leaves the x-ray tube & before it reaches the object
Radiolucent
Permitting the passage of x-rays or other forms of radiant energy with little attenuation
Radiopaque
Not easily penetrable by x-rays or other forms of radiant energy
Remnant radiation
Radiation resulting after the x-ray beam exits the object
Scatter radiation
Radiation produced from x-ray photon interactions with matter in such a way that the resulting photons have continued in a different direction
Source to image distance (SID)
Distance between the source of the x-rays & image receptor
Spatial resolution
Degree of accuracy of the structural lines actually recorded in the image
Umbra
True edge of an object as imaged radiographically
Window level
Image manipulation parameter that changes image brightness on the display monitor, usually through the use of a mouse
Window width
Image manipulation parameter that changes image contrast on the display monitor, usually through the use of a mouse
Attenuation
Process by which a beam of radiation is reduced in energy when passing through tissue or other materials
Brightness
Function of a display monitor; changes image lightness/ darkness
Contrast
Difference between adjacent image receptor exposures on a radiographic image
Density
Degree of darkening or blackness of exposed & processed photographic or radiographic film
Exposure indicator (EI)
Numeric representation of the quantity of exposure received by a digital image receptor
Distortion
Misrepresentation of the true size or shape of an object
Grid
Device consisting of thin lead strips designed to permit primary radiation to pass while reducing scatter radiation by absorption
Image receptor (IR)
Medium used to capture the image for recording, such as x-ray film or a digital imaging plate
Kilovolt peak (kvp)
Measure of the potential difference, which controls the quality and affects the quantity of x-ray photons produced in the c-ray tube
Milliampere second (MAS)
Measurement of milliamperage multiplied by the exposure time in seconds, which controls the total quantity of x-ray photons produced in the x-ray tube
