Prime Factors Flashcards
The emission (production) of x-ray photons is controlled by…
- X-ray tube construction
- Filtration (get rid of long wavelengths)
- Tube housing
- Prime factors
Does the RT have control over prime factors?
Yes
What are the 4 prime factors that affect the emission of x-rays (in overhead tube)?
- Kilovoltage (kVp)
- Milliamperage (mA)
- Time or seconds (s) - note: mA x s = mAs
- Distance ([D] = SID)
Prime exposure factors are ____ the technologist ___.
The technologist’s job is to know how to ___ these ___ to produce _____.
Prime exposure factors are VARIABLES the technologist CONTROLS.
The technologist’s job is to know how to COMBINE these FACTORS to produce HIGH QUALITY RADIOGRAPHS.
What 2 factors affect x-ray emission? What do they measure?
- Quantitative factors - measurement of the number of x-ray protons in useful beam
- Qualitive factors - measurement of the penetrating ability of the useful beam
Name some quantity factors as well as quality factors
Quantity factors - mA, seconds, kVp, distance, filtration
Quality factors DEPEND ON kVp, filtration
Milliamperage
- ___ is the standard abbreviation
- measurement of the _____ or ____ of ___ flowing per ___
- ___ controls the ____ that is applied to the ___
- as ___ increases, so does the number of ___ flowing from the ___ to ___ in X-ray tube
Milliamperage
- mA is the standard abbreviation
- measurement of the TUBE CURRENT or NUMBER of ELECTRONS flowing per SECOND
- mA controls the HEAT that is applied to the FILAMENT WIRE
- as mA increases, so does the number of ELECTRONS flowing from the CATHODE to ANODE in X-ray tube
mA and quantity are…
which means…
mA and quantity are DIRECTLY PROPORTIONAL
which means IF THE mA IS DOUBLED, SO IS THE QUANTITY OF TUBE CURRENT OR ELECTRONS
What are the common diagnostic ranges of mA stations?
- 200 to 400 mA will…
- 800 to 400 will…
What are the common diagnostic ranges of mA stations? 20 mA - 1200 mA
- 200 to 400 mA will DOUBLE AMOUNT OF TUBE CURRENT OR NUMBER OF ELECTRONS “BOILED” OFF OF THE FILAMENT
- 800 to 400 will CUT THE NUMBER OF ELECTRONS IN HALF
Define time/seconds
as exposure time increases…
What will 0.05 to 0.10 do?
What will 0.8 to 0.4 do?
Define time/seconds - LENGTH OF TIME THE HEAT IS APPLIED TO THE FILAMENT WIRE
as exposure time increases, MORE ELECTRONS ARE BOILED OFF THE FILAMENT WIRE
What will 0.05 to 0.10 do? DOUBLES THE ELECTRONS
What will 0.8 to 0.4 do? HALVES THE ELECTRONS
Time or seconds of exposure and quantity are…
Time or seconds of exposure and quantity are DIRECTLY PROPORTIONAL TO THE NUMBER OF TUBE CURRENT OR ELECTRONS OR X-RAY PHOTONS
Time selections
- short exposure times are…
- older equiptment expresses time in…
- new equiptment expresses time in…
Time selections
- short exposure times are USEFUL IN REDUCING MOTION ARTIFACTS
- older equiptment expresses time in FRACTIONS
- new equiptment expresses time in SECONDS OR MILLISECONDS (ms)
mA and seconds are directly ____ to the ____
- if the mA or seconds doubles, so does the ____ or ___ of _____
- if the mA or seconds is cut in half, so does the _____ or ___ of _____
mA and seconds are directly PROPORTIONATE to the TUBE CURRENT
- if the mA or seconds doubles, so does the TUBE CURRENT or NUMBER of ELECTRONS
- if the mA or seconds is cut in half, so does the TUBE CURRENT or NUMBER of ELECTRONS