30 terms

Radiology Terminology week 3

A device that measures the optical density on a film.
Gross fog
the total density of base plus fog is often referred to as basic fog or gross fog
is a convenient darkroom feature when there is a frequent need to transfer film to and from the darkroom while it is in use.
A device that prints a standard gray scale of densities on radiographic film
film bin
is a special container in the darkroom to hold film for reloading cassettes
is radiation from the cassette back and the cassette tray that is scattered back toward the film.
Grid cassette
is a special cassette with a grid built into the front side. Both portable grids and grid cassette with a grid cassettes are used for mobile and surgical radiography and for special applications when the patient cannot be positioned on the table or at upper ratios than the grids used in permanent installations.
Scatter radiation
The result of either coherent scattereing or the compton effect is usually know as this.
Compton Effect
occurs at energy levels throughout the diagnostic x-ray range. The incoming x-ray photon interacts with an outer orbital electron of an atom, removing it from the atom and then proceeds in a different direction.
the tool for body part measurement
Technique Chart
is a listing of the various radiographic examinations performed in the facility. It provides exposure factors for each body part according to its thickness.
Crescent mark
An artifact formed by attempting to hold a film horizontal with one hand and allowing it to bend.
are special light fixtures fitted with filters, will only permit the passage of light frequencies to which the film is least sensitive.
are marks, exposures, or images on the radiograph that are not part of the intended image.
Focused grid
Grids for general-purposes use, because the lead strips are aligned to the direction of the diverging primary x-ray beam.
photoelectric effect
is similar to that which forms characteristic radiation in the x-ray tube .
grid frequency
the number of lead strips per inch
Secondary radiation
Radiation produced by the photoelectric effect .
air gap
Its name implies, is an air space between that patient and the film. In other words, Large object-image receptor distance (OID).
radiographic phantom
is a human skeleton, or portion of a skeleton, encased in a plastic material that is similar in density to human tissue.
Computed radiography
is one of the two types of digital imaging systems; Was introduced in the United States in 1983 by Fuji Medical Systems of Japan.
Digital radiography
is a second type of digital imaging system
Manual film processing system
consists of a large tank plumbed for constant water flow. The flow rate should be sufficient to provide eight complete changes per hour.
Film Dryer
The dryer section of the processor consists of air tubes with long slits. The air tubes are mounted on both sides of the of the dryer rack, directing warm air at both sides of the film as it passes through this portion of the roller system.
Parallel grid
A grid with strips that are parallel to each other, rather than focused.
Compensating Filter
To compensate for these variations in tissue density, specially desined attenuating devices, which can be placed between the radiographic tube and IR.
Optimum kVp
The best policy is to use the highest kVp setting that will produce sufficient contrast for acceptable image quality.
the normal variation of a small sesamoid bone located posterior to the knee
pedal digit
the phalanges comprise the toes.
grid lines
Or also grid stripping, the grid absorbs some useful radiation, the radiographic image includes an image of the grid itself.