Method of transporting energy through space. X-ray:
A form of electromagnetic radiation similar to visible light but of shorter wavelength:
A number of x-rays traveling together through space at a rapid speed:
Physical properties of X-rays
_______ is variable and is related to the energy of the radiation.
The travel of an X-ray is:
X-rays are able to penetrate materials that absorb or reflect_____.
Certain substances will _______ after absorbing electromagnetic radiation
X-rays produce an invisible image on photographic film that can be made visible by_______.
X-rays can cause ________ in living tissue.
Discovery of the x-ray:
> Wilhelm Roentgen
> Wurzburg, Germany
X-rays were originally called:
X-rays can cause 2 different biological changes to living tissue:
>________ cells in the body
>________ reproductive cells
__________, the ease by which you see a radiograph. Depends on density, contrast, and geometric factors.
The degree of blackness of a radiograph. It is influenced by the quantity and quality of the x-ray beam as well as type and ______ of the tissue. What is it?
Factors affecting density:
> total number of x-rays
> penetrating power of the x-ray
> developing time
> developer temperature
The visible difference between adjacent radiographic densities. Two categories:
Radiographic contrast is influenced by:
> subject contrast
> kVp level
> scatter radiation
> film type
> film fog
The density difference between adjacent anatomic structures. There should be varying shades of black, gray and white.
The mA's will affect contrast only when _______ or ________ mA's is used. When a correct mA's is used the contrast is dependent on the _____ setting.
> excessive, insufficient
kVp can affect both ______ and ______. If insufficient kVp is used the film will have an overall _______ appearance and subject contrast is _____. If excessive kVp is used ________ will be evident; film being too dark or "burned".
Non-image forming radiation that is a result of the primary beam not being focused on the patient or being delivered at to high a rate.
To prevent scatter radiation you must use:
>appropriate kVp>appropriately collimate
>utilize a grid in tissue densities over 10cm
A device placed between the patient and the film that is designed to absorb scatter radiation.
Composed of alternating lead strips and spacer material, may be as many as _____ lead strips. It is designed to allow the majority of the primary beam to reach the patient while absorbing unused radiation.
Types of grids:
> linear grid
> crossed grid
> focused grid
> unfocused grid
Device that is built into the table to hold the grid and allows the grid to move across the beam. This will eliminate line and helps to absorb the radiation.
Two examples of geometric distortion:
A rigid film holder designed to hold the film and intensifying screens in close contact.
Cassettes can be made from:
the back is normally made of _____ to absorb scatter.
>magnesium, and carbon fiber
Some cassettes have a small rectangular area in one corner called a _______. It's purpose is to not allow exposure to that area for imprinting purposes.
Cassette sizes vary, but the ones we use at Tomball are:
Cassettes can be damaged in two ways:
>dropping the cassette
>spilling fluid onto cassette
_____ are luminescent phosphor crystals bound together and mounted on a plastic base.
The purpose of intensifying screens is to reduce the amount of radiation exposure needed to produce the __________. The use of screens results in ________. ___% should be produced by the intensifying screen.
>lower mA usage
Screen layers within a cassette:
>support or base
>phosphor crystal layer
>______ developed in 1896 by Thomas Edison. Blue light sensitive
>______ developed in 1972. Green light sensitive
>high definition, maximum detail
>most commonly used in veterinary medicine
>reduce exposure times, thick tissue densities
Purpose is to create a permanent record
Film speed: (most widely used)
>medium - widely used
Proper film care:
>awareness of expiration date
Before we had imprinter cards we had:
> lead tape
> lead markers
Boundaries for a thoracic x-ray:
>______ and ______
> scapular-humoral joint and thoracic vertebrae
When developing, the rule of thumb concerning the temperature of the developer:
>warmer the water the lesser the time it takes to develop
Problems we can have with the x-ray and how the x-ray is made:
>filament lifespan: wears out, fails
>bearing damage on rotating anode
>damaged glass envelope - fractured
Measures the patient area. Always read bottom of bar in ____.