Chapter 3
What controls the quality & penetrating power of the photons?
KVP
The tech benefits when the patients dose is minimal, why?
There is less scatter coming from the patient.
What does scatter cause to appear on the radiograph?
Radiographic Fog
Who founded x-rays? What year & what was his first x-ray?
Wilhelm Roentgen, 1895, his wifes hand
What is Air Kerma measured in?
Gray (Gy)
When an x-ray enters the human tissue, what are the 3 possibilities that can happen?
absorbed by the body, scattered, or pass through w/ no interaction.
The target is known as which part of the x-ray tube?
What is the target made of?
Anode
Tungsten
What are the 5 types of interaction?
Coherent, Photoelectric absorption, compton, pair production, and photodisintegration.
In ___ radiologist and dentist starting seeing _____ appear on their hands, which led to _______.
1910, lesions, cancer
Radiation with a higher LET causes less or more damage to the body's tissue?
More.
What is it called when the energy from the xray is transferred to the patients biologic material.
Absorption
The target is made of certain material that has these 2 characteristics, what are they ?
High melting points + high atomic numbers
Which two interactions are important to radiology?
Compton and Photoelectric
In what year did they decide to begin using the international system of units?
1985
The TEDE limit is ___sv for occupational & ____ sv for the general public.
0.05 & 0.001
What is the amount of energy absorbed per unit mass called?
Absorbed Dose
The glass window and aluminum in the collimator make up what?
Permanent inherent filtration
Who was Thomas Edison's assistant who died from cancer?`
Clarence Dally
What are the 5 radiation quantities?
Exposure, Air Kerma, Absorbed Dose, Equivalent Dose, & Effective Dose
What is the formula for Equivalent Dose?
EqD= Absorbed Dose (D) x Weighing Factor (Wr)
Direct transmission is what?
Photons travel through a patient without interacting
_____ is when an xray passes through a patient.
Attenuation
What is a crookes tube?
an evacuated, pear shaped glass tube.
Exposure is the total electrical charge w/ photon energy up to _____ eV
3 million
What is the formula for Effective Dose
EfD=absorbed dose (D) x weighing factor (Wr) x tissue factor (Wt)