Recording The Image Flashcards
How do the digital electrical signals work?
They are used to create pixels that form a visible radiographic image on the monitor
What do digital image receptors do?
Convert an analog signal into a digital electrical signal
True or false: digital image receptors may resemble and be used in the same manner as a conventional x Ray film cassette
True
What are three advantages of digital image receptors over conventional x Ray film?
Eliminates the need of X-ray film processing
Better images that are made faster
Images can be manipulated
Can CR systems be used for horizontal and vertical film images?
Yes
What are four controllable components of the X-ray?
Milliamperes he
Exposeur time
Kilovolt age peak
Focal film distance
What is milliamperage?
Measure of the electrical current that is used to heat the wire filament at the cathode
The temperature of the filament is directly related to what?
The # of electrons that freed from their orbits to travel to the anode
What is exposeur time?
Controls the period of time during which X-rays are actually produced in the X-ray tube
What is exposeur time equivalent to?
The amount of X-rays produced
What controls the number of X-rays produced?
mA and exposeur time
How can you reach mA-s requirements?
By adjusting mA and exposeur time
300mA x 1/60s= what?
5ma s
What is kilovolt age peak?
Measure of electrical potential difference between the cathode and anode
X-rays of higher energy can do what?
Have greater potential to penetrate through tissue
What is the focal I’ll distance
The distance between the focal spot in the x Ray tube and the X-ray film
What does the focal film distance effect?
The number of Rays that reach the film during a radio graphic exposure
What is the inverse square law?
The intensity of the beam is reduced by 1/4th when you double the distance from the source
The visual quality of a radiograph image is assessed by what?
Density
Contrast
Detail
Distortion
What is density?
The degree of blackness on a film
What does density depend on?
The number of X-rays reaching the film
What will the number of X-rays do to density?
The more x Rays to reach the film, the greater the blackness and the greater the density
How does mA s affect density?
Determines the # of x Rays produced
How does kVp effect density?
Determined penetrating power of X-rays
How does FFD effect density?
The farther the film from the tube the fewer X-rays that will hit which will cause lower density
How can film processing and patient factors effect density? 4
Developing time
Developing temperature
Tissue thickness
Tissue density
What is radio graphic contrast?
Visible difference between two adjacent structures on a film
What will high contrast look like?
Lots of Black and white little grey
What is low contrast?
Lots of grey, little black and whit
How can kVp effect contrast?
Variations and penetrating power can create more or fewer shades of gray
What can effect contrast?
Differences in tissue thickness/density and scatter radiation
What is radio graphic detail?
Image sharpness, clarity
What are four factors that effect radio graphical detail?
Focal spot size, FFD, animal motion, screen film contact
What are three ways to prevent radio graphic distortion?
Positioning subject as close to the cassette as possible
Positioning point of interest in the center of the x ray beam
Positioning subject parallel to cassette
What is the radio graphic image lattitude?
The exposeur factor setting range over which radio graphic images of adequate radio graphic density will be produced
Why does X-ray film require settings to be exact?
Because of its narrow lattitude
Why do digital x Rays not need I be as exact?
Because digital takes x rays over a wide range of exposure settings
Why can digital produce more shades of grey?
Because of its wide latitude
