Ch.3 Flashcards
If x-rays enter a material such as human tissue, they may
- Be absorbed
- Be scattered
- Be transmitted
Only important types of interactions between x-radiation and matter in diagnostic radiology
Compton, Photoelectric (?)
What is a tech’s biggest source of scatter ?
The patient
When the positron comes to rest, it will combine with any electron and the mass of both particles is converted into energy
Annihilation radiation
During ________ photons strike the image receptor.
Transmission
Partial absorption of the incident x-ray photon. Incident x-ray photon interacts with an outer shell electron of a target atom and removes the electron. Some of the photon energy is transferred to the ejected electron. The remaining energy of the x-ray photon undergoes a change in direction and is given off in the form of a scattered photon.
Compton scatter
Incident X-ray photon interacts with a target atom and excites the atom. No orbital electrons are ejected, no ionization takes place. Contributes to ESE only.
Coherent scatter
Total absorption of the x-ray photon. Incident x-ray photon interacts with an inner k shell electron of a target atom and removes the electron. All of the remaining energy of the incident photon is transferred to the ejected photon (photoelectron)
Photoelectric absorption
X-ray photon interacts with the nucleus of a target atomic
Pair production
Some primary photons will traverse the pt without interacting and reach the IR
Direct transmission
Other primary photons can undergo Compton and/or coherent interactions and as a result may be scattered or deflected with a potential loss of energy
Indirect transmission
This is the most important mode of interaction between x-ray photons and the atoms of the patients body for producing useful images
Photoelectric absorption
What is the diagnostic radiology energy range
23-150 kvp
Less attenuation causes more _______ on the image
Darkness
More attenuation causes more ______ in the image
Light/grays
