Term
| what is coherent scattering also known as? |
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Definition
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Term
| coherent scatter occurs at what energy level? |
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Definition
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Term
| relationship between incident x-ray and scatter x-ray in coherent scatter |
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Definition
| same energy and same wavelength |
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Term
| what is the result of coherent scatter |
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Definition
| change in direction of x-ray without a change in energy (no ionization) |
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Term
| coherent scatter in relation to diagnostic radiology |
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Definition
| little importance but does contribute slightly to film fog |
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Term
| in compton scatter what does the incident x-ray interact with |
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Definition
| an outer shell electron, ionizing the atom |
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Term
| in compton scatter what is the ejected electron called |
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Definition
| the compton electron or secondary electron |
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Term
| what is the relationship between energy and wavelength in compton scattering |
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Definition
| the scattered electron has less energy and longer wavelength |
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Term
| at what angle does the scattered x-ray defelct at in compton scatter |
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Definition
| can be deflected at any angle |
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Term
| how does compton scatter affect an image? |
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Definition
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Term
| compton scatter is the source of what type of radiation exposure |
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Definition
| occupational dose by the rad tech (mainly during fluoro) |
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Term
| what type of electron does an incident ray interact with during photoelectric effect |
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Definition
| an inner-shell electron and then ejects it causing ionization |
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Term
| what happens to the incident ray in photoelectric effect |
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Definition
| it is totally absorbed, releasing all of it's energy to the ejected electron |
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Term
| what is the ejected electron called in photoelectric effect |
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Definition
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Term
| in photoelectric effect what happens when outer-shell electron fill in the spaces of void left by ejected electron |
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Definition
| characteristic x-rays (secondary radiation and behave the same as scatter radiation) |
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Term
| how does photoelectric effect effect the image |
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Definition
| it is responsible for image contrast (white areas) |
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Term
| how much energy is necessary for pair production |
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Definition
| 1.02 MeV => it has to be that high to get close to the nucleus of the atom (does not occur in diagnostic imaging) |
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Term
| what happens in pair production |
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Definition
| the interaction between the x-ray and the nuclear electric field causes the x-ray to disappear, and in its place two electrons appear, one positively charged (positron) and one negatively charged |
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Term
| what energy level do you need for photodisintegration |
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Definition
| 10 MeV in order to interact with nucleus of an atom (not in diagnostic x-ray) |
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Term
| what happens in photodisintegration |
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Definition
| the energy is absorbed by the nucleus and the nucleus emits a nuclear fragment |
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Term
| what is differential absorption |
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Definition
| the difference in x-ray interaction resulting from the differences between x-rays that are absorbed photoelectrically in the patient and those that are transmitted to the image receptor |
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Term
| what 2 types of interactions with matter cause differential absorption |
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Definition
| compton scattering and photoelectric effect, and x-rays transmitted through the patient |
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Term
| how many x-rays reach the image receptor |
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Definition
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Term
| how many of the x-rays that reach the image receptor interact to form an image |
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Definition
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