2b Diff. Medical Imaging Flashcards
List of diagnostic imaging studies
Plain x-rays
CT scan
MRI
Nuclear imaging/PET
Ultrasound
Mammography
Angiography
Fluoroscopy
What are x-rays?
No mass
No charge
High Energy EM radiation
Short wavelength
Diff. tissues absorb diff. amounts of radiation
a form of electromagnetic energy
X-rays
Travel at the speed of light
X-rays
Electromagnetic spectrum
Gamma Rays X-rays
Visible light Infrared light
Microwaves Radar
Radio waves
Three things’ X-rays can happen
Pass all the way through the body
Be deflected or scattered
Be absorbed
X-rays Passing Through Tissue
- Depends on the energy of the x-ray and the atomic number of the tissue
- Higher energy x-ray - more likely to pass through
- Higher atomic number - more likely to absorb the x-ray
X-rays that pass through the body to the film render the film dark
black
X-rays that are totally blocked do not reach the film and render the film light
white
low atomic # = x-rays get through = image is dark
Air
high atomic # = x-rays blocked = image is light (white)
Metal
5 Basic Radiographic Densities
Air
Fat
Soft tissue/fluid
Mineral
Metal
Bone composition: living bone contains ________ water
10%-20%
Bone composition: living bone contains ________bone minerals
60%-70%
Optimal Viewing
Dedicated light source
Darkened environment (like a movie theater)
Limit distraction
What are the 5 basic radiographic densities from black to bright white?
Air
Fat
Soft tissue/fluid
Bone/mineral
Metal
Any structure, normal or pathologic, should be analyzed for:
Size
Shape and contour
Position
Density (You must know the 5 basic densities)
What three things can you do to protect yourself from radiation?
By wearing protective gear, Limit exposure, and regular maintenance of the equipment.
How is it possible to see the heart on an x-ray?
Yes it is possible to see the image of the heart (under soft tissue rad. density)
What 3 things when an x-ray encounters the body?
Blocked (deflected or scattered), absorbed and or pass through.
