Ch.14 mAs Flashcards
What happens when selecting mAs on the control console?
- It taps off the resistors in the filament circuit
- Small resistors equal more intense flow rate
- High mA equals higher electricity through the filament (large)
What is mAs?
- The quantity of electric current
- Electrons movement down a wire per second
- Primary electrical control
The intensity rate of the X-ray beam is ____ controlled by the mA station set at the console.
Directly
Double mA=twice as much electron beam per second
What is the proper term for mAs?
Roentgens/sec
If you increase mAs what happens to patient exposure?
It increases
High mA is desired for which type of procedures?
Chest and abdomen
Because patient exposure is more important than fine detail so we use a large focal spot with the high mA
For long exposure times the mA should be what?
Low
Which type of procedures would you use a longer exposure time and low mA?
Tomography and for breathing techniques
With low mAs values there are few photons striking the plate and the uneven distribution is visible with a grainy image. This describes what?
Quantum Mottle
What does it mean when you have Quantum Mottle?
That there are an insufficient amount of photons that have reached the IR
Quantum Mottle is a factor is SNR… What does this stand for?
Signal to noise ratio
Which type of systems are sensitive to quantum mottle?
Digital systems
How can you tell if images are over or under expose in digital radiography?
By checking the exposure index readout
mAs is a factor on determining what in relation to the image produced?
- Brightness
- Noise/quantum mottle
mAs has no relation to changes in what with regards to the final image?
Contrast
Sharpness
Magnification
Shape distortion
