Review Questions Flashcards
Digital fluoroscopy eliminates which of the following?
1. The need for a radiographer
2. Postprocedure “overhead” image
3. Image acquisition
4. Accurate positioning
Postprocedure “overhead” images
What is the smallest particle of an element that retains characterstics of the element?
Atom
In digital fluoroscopy, the image must be turned into digital form by what device?
Analog-to-digital converter
X-ray travels as bundles of energy called?
Photons
What is the atomic mass?
1. The number of photons + neutrons
2. The number of photons
3. The number of electrons
4. The number of photons + electrons
The number of photons plus the number of neutron
What device may be used to ensure consistancy of radiographic quality from one expoure to the next?
Automatic exposure control (AEC)
When a predetermined level of ionization is reached in the ionization chamber, what does the machine do?
The exposure is terminated
Exposure time is very dependent upon kVp
What type of x-ray machine uses a continually decreasing mA for the shortest times possible?
Falling load generator
Uses the max heat storage capacity at every mA & time combo
What type of current is required for proper operation of the x-ray tube?
1. Direct
2. Falling load
3. Alternating
4. Fluctuating
Direct
This necessitates the using of a rectiier to change AC to DC
The law stating that the outer shell of an atom can contain no more than eight electrons is called?
Octet rule
It does not stipulate that there MUST be 8 electrons in the outer shell
Examples of particulate radiations are:
1. X-ray, gamma rays, and cosmic rays
2. Helium nuclei and beta particles
3. Electrons, protons, and meteorites
4. X-ray and quarks
Helium nucleai and beta particles
Particulate radiations are highly ionizing
Electromagnetic radiation travels…
In waves as a straight path
Electromagnetic radiation travels in bundles of energy called?
Photons
At what speed do x-rays travel at?
The speed of light - 186,000 miles per second
Waves of radiation are called?
Sine waves
Wavelength and frequency are inverse to one another
Wavelength is defined as the distance from __ to __.
Peak to peak
Frequency is defined as?
The number of waves passing a point per unit time
Higher frequency = shorter wavelengths; lower freq. = longer wavelengths
The speed of x-ray is based on?
1. mAs
2. kVp
3. Size of patient
4. The fact that they are a form of electromagnetic radiation
The fact that they are a form of electromagnetic radiation
All x-rays travel the same; The speed of light
Wavelength and frequency are what to eachother?
Inversely proportional to eachother
The x-ray beam changes as it travels through the patient by process of?
Attenuation
The x-rays may be absorbed or scattered