physical xray Flashcards
- When electrons pass from a high energy level to a low energy level through WAVES;
- The emission of excess energy is in the form of :
“electromagnetic
radiation”
why do energy decreases in EMR while transferring energy?
due to ABSORPTION AND SCATTERING
in EMR, THEY TRANSFER ENERGY TO THE …………..
MEDIUM THEY PASS THROUGH
EMR with enough
energy to eject orbital
electrons from an
atom is called……………
ionizing radiation
examples of ionizing EMR
UV light, X-rays, gamma-ray
structures with which feature absorb more x-ray and lets less x-ray reach the detector back?
The structures with
higher atomic number,
physical density and
thickness
What is EMR?
When e- pass from HIGH to Low energy lvl
What does the energy consist of in an EMr?
electric field (E) [longer wave] and magnetic field (B)[shorter wave]
As the frequency increases…what happens to wavelength and energy?
Wavelength decreases and energy increases
What is the most largest source of radiaton?
-Radon environment
What is radon?
All earth based materials such as concrete, bricks, wall-board etc contain radon.
What is the largest source of artificial [man-made] ionizing radiation?
Diagnostic x-ray
Which type of cells are more sensitive to radiation?
Proliferating cells[stem cells]
List the most sensitive cell(most proliferation) to most resistant cells (least proliferation)?
WBC(lymphocytes)
RBC
Digestive syst cells
Reproductive organ cells
Skin cells
Blood vessels
Tissue cells(bone,nervous system)
Wht is the role of the generator of the x-ray?
GENERATOR PROVIDES APPROPRIATE
ENERGY TO THE X RAY TUBE
What are the controls found on the control panel of x ray?
X-ray voltage setting
X-ray current setting
Time setting
which part of the control panel control the intensity of the energy?
X-ray voltage [kilovolt potential (kVp)] setting
which part of the control panel control the amount of radiation emitted?
X-ray current[mAmperes] setting
Time setting
How does x-ray form?
Energy[heat]—>Electrons move from cathode to anode—>energy is LOST—>x-ray
With what does x-ray interact with in the matter it is penetrating?
With the ATOMS of the matter
What are the 2 types of x-ray interactions with matter?
1-Absorption
2-scattering
What are the diagnostic features of x-ray
- Penetration;
- Photographic effect;
- Fluorescence effect; fluoroscopy; real-time x-ray movement
- Ionization effect;
**what happens when there’s more attenuation of the x-ray?
less x-rays reach the image receptor (film)→ white «radiodense»[radioopaque]
**what happens when there’s Less attenuation of the x-rays?
more x-rays reach the image receptor(film)→black «radiolucent»
give examples for the 5 main densities in radiographs
(from very Radiolucent[dark] to very radio-opaque[white])?
- Very Radiolucent : Air / Gas
- Radiolucent : Fat
- Intermediate density : Water / Soft tissue
- Radio-opacity : Calcification / Bone / stone
- Very radio-opaque : metal / contrast material
*Organs and tissues that are normally not seen, can be rendered
visible by injecting …………. into or around them.
contrast material[dye]
what is an ex of negative contrast material?
air/CO2 –>give Radiolucent appearance
…………….are materials with high atomic numbers,
so their ability to weaken the x-rays is high
Positive contrast materials
Two types of positive contrast
media are used?
ionized contrast
media and Barium sulphate.
