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The Prime Factors
Principles of Radiographic Imaging 5th Edition Chapter 11
Question | Answer |
---|---|
An increase in kVp by 15% that causes doubling in exposure and vice versa | 15 Percent Rule |
A direct relationship is necessary to compensate for the changes in intensity and film density film density | Direct Square Law |
A direct square law, mAs must increase when distance increases and vice versa in order to maintain image receptor exposure | Exposure Maintaince Formula |
A measurement of x-ray tube current, the number of electrons crossing the tube from cathode to anode per second | Milliamprage(mA) |
The product of tube current(mA) and exposure time(s) | Milliamprage Per Second(mAs) |
The ability of the x-ray to pass through structures and tissues | Penetrability |
Factors related to x-ray emission that are under direct control of the radiographer; Milliamprage(mA), kilovoltage(kVp), and distance(d) | Prime Factors |
The density of an x-ray should remain unchanged as long as the intensity and duration of the x-ray exposure remains unchanged | Reciprocity Law |
A measurement of the penetrating ability of the x-ray beam | X-Ray Quality |
A measure of the number of x-ray photons in the useful beam | X-Ray Quantity |
What are the three prime factors that affect x-ray emmision? | Milliamprage(mA), kilovoltage(kVp), distance(d) |
What is the unit of measurement for x-ray quantity? | Roentgen(R) |
Define ampere | The unit of current, also known as amp |
What is the relationship between mAs and density/IR exposure? | Exposure is directly proportional to mAs, mAs is used as the primary controller of radiographic film density and image receptor exposure |
What effect does increased kVp have on the speed and energy of the electrons in the x-ray tube? | Increasing the kVp will cause an increase in the speed and energy of the electrons applied across the x-ray tube applied across the x-ray tube. |
What is the relationship between kVp and density/IR exposure? | kVp is the primary controller of the differences in densities/IR exposures |
State the inverse square law. | The intensity of radiation at a given distance from a point source is inversely proportional to the square of the distance |
What is the relationship between distance and density/IR exposure? | X-ray intensity will decrease as the distance from the tube is increased |