Rad Quality 2- Exam 1- Review Material from Rad Quality 1

Which interaction is primarily responsible for producing a usable x-ray image on the image receptor?

Photoelectric effect

Which interaction is responsible for for film fogging/noise that degrades the image quality?

Compton effect or scatter

Which interaction is responsible for the production of the primary X-rays produced in the tube?

bremsstrahlung radiation

99% of the energy put into the x-ray system is?

Lost as heat

(1% of all the electrical energy into the system is used to make X-rays)

What 3 alterations does the tube make to deal with the heat produced from forming X-rays without damaging the machine/tube?

Uses high melting point Tungsten metal in the anode and cathode

Anode spins to dissipate heat

Entire inner tube is placed within oil to help cool the internal mechanisms

The cathode is_________charged

Negatively

The anode is _______ charged

Positively

What does the difference in charge between the cathode and anode allow for?

Helps the negatively charges electrons repel the cathode and crash toward the anode when the exposure button is pushed

How do you find out the amount of radiation exposure that is occurring?

Multiply the given mA by the amount of seconds to get mAs

-higher the mAs the more radiation

What is a dual focus probe?

2 focal filaments in the cathode and 2 focal spots in the anode (named large and small, respectively)

What are the pros and cons of a dual focus probe with large focal spot

Large focal spot/filament= produces many X rays and helpful for imaging large areas and patients; increases penumbra

What are the pros and cons of a dual focus probe with a small focal spot

Small focal spot/filament= can not produce many x-rays, has excellent resolution (minimal penumbra), great for assessing smaller areas of the body and looking for subtle fractures

Why not always use the small focal filament/spot if the image quality is better?

Exposure times would be significantly longer and increase the chance for patient movement which would generate the image quality as a patient motion artifact

What is it when something is under exposed?

Too white= need more X-rays

2x mAs or increase kVp by 10-15%

-if you see the bones leave the kVp alone

What is it when something is over exposed?

Too dark= need less x-rays

1/2 the mAs or decrease the kVp by 10-15%