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77 Cards in this Set
- Front
- Back
X-ray Interactions with Matter ((test)) What are the 5 different interactions with matter? |
1. Classical scattering 2. Compton Effect 3. Photoelectric Effect 4. Pair production 5. Photodisintegration |
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Classical Scattering ((test)) Give the 3 names it is known as? |
1. Coherent 2. Thompson 3. Rayleigh scattering |
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Classical Scattering ((test)) What type of energy is produced? |
Low |
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Classical Scattering ((test)) Classical Scatter produce low- energy x-ray photons. How many kev is used? |
Below 10 kev |
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Classical Scattering ((test)) Incident x-rays and scattered x-rays have equal? |
Wavelength and Energy |
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Classical Scattering ((test)) As an incident x-ray slightly changes direction without changing it's energy, what type of x-ray will occur? |
Scattered x-ray occurs |
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Classical Scattering What happens in a Classical Scattering? |
1. Incident x-ray interacts with target atom 2. Incident x-ray changes direction without change in energy 3. Scattered x-ray occur |
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Compton Effect Give the 2 different names it is known as? |
1. Compton scattering 2. Modified scatter |
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Compton Effect ((test)) Define Compton effect? |
Incident x-rays interact with outer shell electron, ejecting it from the atom and ionizing the atom causing the photon to change direction with less energy. |
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Compton Effect What is the ejected electron known as? Give 2 names... |
1. Secondary electron 2. Compton electron |
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Compton Effect The energy of a scattered x-ray equal to the difference between energies of ? |
Difference between the energy of incident x-rays and energy of ejected electron |
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Compton Effect Can be transmitted through the body, absorbed, scattered out of the body, what type of effect is this? |
Compton effect |
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Compton Effect The energy of ejected electron equal to? |
It's binding energy plus kinetic energy when leaving the atom. |
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Compton Effect Usually the scattered x-ray retains most of its energy. How much of it's original energy? |
Two thirds its original energy |
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Compton Effect Define Back scatter radiation |
X-rays that have interact with object and deflected backwards. |
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Compton Effect What is the probability of Compton effect dealing with energy? |
Decrease as energy increases because increase in penetration through tissue without interaction. |
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Compton Effect What is the probability of Compton effect related to? |
Photoelectric effect |
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Compton Effect What is the probability of a Compton effect if there is higher energy? |
Low Compton effect |
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Compton Effect What is the probability of Compton effect with atomic number? |
Compton effect is NOT dependent on atomic number. |
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Compton Effect How are x-ray effected with the probability of soft tissue or bone? |
Any x-rays is the same as soft tissue or bone because it is not dependent on atomic number. |
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Photoelectric Effect (test) What happens in Photoelectric effect? |
Incident x-ray interact with inner shell electron,and ionizes the atom. Ejects a photo-electron, but the x-ray is absorbed and not scattered. |
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Photoelectric Effect ((test)) What do the photo-electrons kinetic energy equal to the difference between the energy of ? |
The difference between the energy of incident x-ray and binding energy of electron. |
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Photoelectric Effect ((test)) What happens to the photoelectron? |
Electron is ejected from k-shell, an outer-shell electron will drop into the vacancy and emit a characteristic x-ray. |
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Photoelectric Effect How will a secondary radiation behave? |
Like scatter radiation |
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Photoelectric Effect ((test)) What does a secondary radiation contribute to an x-ray image? |
Nothing useful to x-ray image. |
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Photoelectric Effect A photoelectric interaction cannot occur unless? |
Incident x-ray had energy equal or greater than electrons binding energy. |
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What do a characteristic radiation and photoelectric effect have in common? ((test)) |
Interact with inner shell electron |
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In the photoelectric effect, what does it do in the body? |
Absorbs |
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Photoelectric effect The probability of an x-ray that will undergo photoelectric interaction depends on what 2 things? |
1. x-ray energy 2. Atomic number |
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Photoelectric effect Energy: The probability of photoelectric interaction is inversely or directly proportional to the third power of the x-ray energy? |
Inversely |
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Photoelectric effect Atomic number: What is the probability of a photoelectric interaction is inversely or directly proportional to the third power of the atomic number of the absorbing material. |
Directly |
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Photoelectric Effect What is the probability of energy if there is a increase in kVp? List 2 things it will effect? |
Increase kVp= 1. Decrease x-ray energy 2. Less photoelectric effect |
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Photoelectric Effect What is the probability of energy if there is a decrease in kVp? List 3 things it will effect. |
Decrease kVp= 1. Increase x-ray energy 2. More x-rays absorb 3. More photoelectric effect |
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Photoelectric Effect What is the probability the atomic number of a photoelectric effect if there is an increase, what will happen to the atomic number? |
Increase in atomic number |
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Photoelectric Effect What is the probability of an atomic number if atoms with high atomic number will absorb______ x-rays? |
More x-rays |
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Photoelectric Effect Why bone absorbs more x-rays than soft tissue? |
Bone has high atomic number |
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Pair Production When does a pair production occur? |
Incident x-rays interact with field of the nucleus |
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Pair Production What happens in pair production? |
Interaction between x-ray and nucleus which causes the x-ray to disappear. In its place 2 electrons appear. |
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Pair Production Incident photon must have Mega Electron Volts (MEV) of energy of? |
1.02 MeV |
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Photodisintegration When does photodisintegration occur? |
Occurs when extremely high energy (10 MeV) is absorbed by the nucleus. |
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Photodisintegration What will happen to the nucleus? |
Nucleus is raised to an excited state and instantaneously emits a nucleon or other nuclear fragments. |
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What interactions can happen? Name 3 things x-rays can do? ((test)) |
1. Absorbed- Photoelectric 2. Scattered- Compton scatter 3. Transmitted- Patient to image receptor |
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A useful beam equals to the differences between...? ((test)) |
Equal to the differences between absorbed photoelectrically and those transmitted |
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Differential Absorption ((test)) List the things that give you differential absorption. What are the 3 different absorption? |
1. Compton scattering 2. Photoelectric effect 3. X-ray transmitted through patient |
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What will give you a diagnostic film? |
Transmitted or Scattered |
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What will give you a useful beam? |
Transmitted or Scattered |
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Differential Absorption ((test)) Define differential absroption? |
X-ray image results from difference between x-rays absorb photoelectrically in patient and those x-rays transmitted to image receptor. |
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Differential Absorption ((test)) What happens in a photoelectric effect when anatomic structures that absorb the x-ray? |
Radiopaque (Useful information/ white image) |
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Differential Absorption Anatomic structures that transmit x-rays equal what type of image? |
Radiolucent |
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Differential Absorption In differential absorption an x-ray image results from what 2 things? |
X-rays absorbed photoelectrically in patient and x-rays transmitted to image receptor. |
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Differential Absorption Difference in x-ray interaction equal to? |
Differential absorption |
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Differential Absorption Differential absorption in bone and soft tissue equal to? |
Equal to Photoelectric interactions, which depends greatly on atomic number. |
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Differential Absorption To achieve optical difference absorption, what must you do? |
You must have proper kVp selection. |
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Depending on Atomic Number Low energies most x-ray interactions equal to? |
Photoelectric |
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Depending on Atomic Number High energies most x-ray interactions equal to? |
Compton |
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Depending on Atomic Number Increase in energy will increase or decrease the chances of interactions? |
Decrease chances of interactions |
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Depending on Atomic Number Small images difference in what 2 things? |
1. Soft tissue-Ex: Mammography 2. Low kVp- Results in maximum differential absorption. |
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Depending on Atomic Number Example: How much more likely is an x-ray to interact with soft tissue than bone? Bone: 13.8 Soft tissue: 7.4 |
Bone: (13.8)^3 Soft tissue: (7.4)^3 2628 Bone / 405 Soft tissue = 6.5 interaction |
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Dependence of Mass Density (test) What is mass density? |
Quality of matter per unit volume (kg/m^3) OR (gm/cm^3). |
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Dependence of Mass Density What is it related to? |
Related to mass of each atom |
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Dependence of Mass Density What does it tell? |
How tightly the atoms are packed together |
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Dependence of Mass Density Which has a higher mass density, bone or soft tissue? |
Bone |
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Dependence of Mass Density Interactions between x-rays and tissue being imaged is directly or indirectly proportional to the mass density of the tissue. |
Directly proportional to the mass density of the tissue |
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Contrast Examination Define Contrast Agent? |
A compound used as an aid for imaging internal organs with x-rays. |
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Contrast Examination Why must the contrast medias need to have a high atomic numbers? |
So that differential absorption to occur. |
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Double Contrast Examinations ((test)) Why do you do this? |
Exam for the colon that uses Air and Barium for contrast. |
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Single Contrast Examination Why do you do this? |
Single contrast Barium Enema |
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Exponential Attenuation What is it? |
Relative frequency of interaction of each mechanism depends primarily on the atomic number of those atoms and x-rays energy. |
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Exponential Attenuation What is Attenuation? |
Total reduction in number of x-rays remaining in x-ray beam after penetration through a given thickness of tissue. |
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Exponential Attenuation What does attenuation equal to? |
Absorption + Scattering. |
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Exponential Attenuation Absorption is what type of interaction? |
All-or Nothing interaction |
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Exponential Radiation Define Remnant Radiation? |
Beam that exits tissue and interacts with film or IR. |
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Radiation Protection: Shielding When should shielding be used? Name 4. |
1. Patient is child- bearing years 2. When gonads lie in or near useful beam 3. As long as it will not interfere with x-ray taken 4. It is is requested by the patient |
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Occupational Exposure Define? |
Dose received by any individual in the course of employment. |
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Occupational Exposure Where can techs. get the most exposure? Name 6. |
1. Portables 2. Fluroscopy 3. C- arm surgery 4. Fluroscopy in department 5. Angiography 6. Cardiac Cath lab |
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Occupational Exposure Where can rads and personnel get less exposure? Name 2. |
1. Tube under table 2. C- arm tube under table |
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Occupational Exposure If you are helping in fluroscopy , what kind of gloves may you use? |
Lead gloves |