Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
|
What is the half value layer?
|
Defined as the amount of material required to reduce the xray intensity to half its original value.
|
|
|
__________ is sometimes called Thompson or classical scattering.
|
Coherent
|
|
|
___________ occurs when a low energy photon impacts with an entire atom without ionizing the atom. The incident photon then changes direction.
|
Coherent Scattering
|
|
|
True or false. Coherent scatter is not a part of diagnostic imaging.
|
True. This is because the kVp would have to be less than 10.
|
|
|
What type of scatter occurs with xray scanners at airports?
|
Coherent
|
|
|
Identify the type of interaction. The incident photon loses some or all of its energy when it impacts with an inner K shell electron and removes it from orbit.
|
Photoelectric effect
|
|
|
When the photoelectric effect occurs the incident photon removes an inner K shell electron from its orbit, the filling of this vacancy produces:
|
A characteristic xray
|
|
|
True or false. Photoelectric interaction rarely produces scatter that exits the patient.
|
True
|
|
|
True or false. Characteristic interactions occur within the patient.
|
False, the tube
|
|
|
True or false. Photoelectric interactions occur within the patient.
|
True
|
|
|
Below 75 kVp, _________ is the most predominant interaction.
|
Photoelectric
|
|
|
Identify the interaction. When an incident photon collides with an outer shell electron, the original photon continues in a different direction minus the energy that it took to remove the electron from its orbit.
|
Compton's
|
|
|
What type of interaction is responsible for the fogging of film due to scatter?
|
Compton's
|
|
|
If the incident photon is at least 1.02 MeV, than a high energy xray is transformed into a positive and negative electron pair when it passes near the atoms nucleus. What is this called?
|
Pair production
|
|
|
If the incident xray is greater than 10 MeV, the nucleus of the atom splits up into fragments. What is this called?
|
Photonuclear disintegration
|
|
|
Incident electrons travel from zero to _______ in 2 cm.
|
Half the speed of light
|
|
|
________ only occurs when the incident electron interacts with the force field of the nucleus of an atom. The electron must have enough energy to pass through the orbital shells of the target atom.
|
Brehmsstruhlung
|
|
|
True or false. The closer the electron is to the nuclei, the more energy is lost, and a high Brehmsstruhlung photon is produced.
|
True
|
|
|
The energy levels of Brehmmstruhlung radiation range from:
|
zero up to the level of kVp set
|
|
|
Characteristic interactions occur in what kVp range?
|
Above 70 kVp only
|
|
|
What is the atomic number of Tungsten?
|
74
|
|
|
What is keV?
|
used to measure intensity of beam and is the binding energy of electrons
|
|
|
Characteristic interactions cause atoms to change temporarily into:
|
positive ions as they lose an electron
|
|
|
Between 80-100 kVp, about 80-90% of the beam is:
|
Brehmmstruhlung
|
|
|
The average primary beam has a peak energy of about ____% of the kVp setting.
|
30-40
|
|
|
True or false. All vascular imaging studies that involve an injection of contrast to visualize the intended structures should start with a scout film of that region.
|
True
|
