4. Radiation Physics Flashcards
What is intensity in the context of the X-ray beam?
Total amount of energy in the X-ray beam.
What controls the quantity of the X-ray beam?
Tube current (mA) and exposure time (sec).
What controls the quality of the X-ray beam?
Tube voltage (kVp).
How does tube voltage (kVp) affect the X-ray beam?
Increases both the number of photons and their energy.
How does exposure time affect the X-ray beam?
Increases the number of photons but not their energy.
How does tube current (mA) affect the X-ray beam?
Increases the number of photons without changing energy.
What is the role of filtration in X-ray production?
Removes low-energy photons, improving quality but reducing quantity.
What is collimation in X-ray production?
Restricts beam size, reducing photon count without affecting energy.
What does the inverse square law state about X-ray intensity?
Intensity decreases with increasing distance; doubling distance reduces intensity by a factor of 4.
How does tube voltage (kVp) influence quantity and quality?
Increases both quantity and quality.
What is the effect of tube current (mA) on quantity and quality?
Increases quantity; no effect on quality.
How does exposure time impact quantity and quality?
Increases quantity; no effect on quality.
What is mAs and how does it affect X-ray quantity?
mA multiplied by exposure time, increases quantity with no effect on quality.
How does source-to-object distance influence X-ray quantity and quality?
Decreases quantity; no effect on quality.
What is the impact of filtration on X-ray quantity and quality?
Decreases quantity and increases quality.
What controls the density of a radiograph?
Controlled by mAs.
How is contrast on a radiograph controlled?
Controlled by kVp.
What are the characteristics of high contrast in radiographs?
Low kVp; high contrast with fewer shades of gray.
What are the characteristics of low contrast in radiographs?
High kVp; low contrast with more shades of gray.
What is the relationship between mA and exposure time in maintaining radiograph density?
Inversely proportional to maintain the same density.
What type of kVp is ideal for caries detection?
Low kVp for high contrast and caries detection.
What type of kVp is ideal for viewing bone loss?
High kVp for low contrast and bone loss visualization.
What are key takeaways regarding beam intensity and exposure factors?
Intensity depends on mA, exposure time, and kVp; filtration improves quality but reduces quantity; collimation shapes the beam and reduces exposure.
