9/6a Intro to Imaging Flashcards
Radiography
Conventional radiograph is generated from x-rays/films that help us to visualize the image of bones
Attenuation
the degree to which the x-rays are absorbed, scattered, or passed right through the body. Dependent on a lot of factors
Factors that impact attenuation of a radiograph
Thickness of the tissue
Atomic number of the tissue
Density of the tissue
What attenuates least in a radiograph?
Air, thus the lungs show up as black in a radiograph
Radiodense
things that absorb and scatter the x-rays to the largest degree are the most - cortical bone is the most radiodense, then spongey
Radiolucent
lungs and gas in the colon - appear black in the image
Radioopqaue
not naturally occurring in the body, so they appear really white (screws, barium swallow, etc.)
Contrast
degree to which two adjacent structures appear different in their quality
T/F: whatever you are interested in should be as close to the recording medium as possible?
TRUE
Standard X-ray layout
A to P projection
-exceptions are: the chest and the hands and feet (P to A projection)
T/F: if oriented correctly, the right side will be the same as your right side
FALSE - the right side will be the opposite of your right side
Positions for x-ray
General body position - anatomical
Specific body position - semi-erect (SE) and weight bearing (WB)
Projection path of the X-ray
A to P
Lateral (as close to 90 degrees from AP plane)
Each joint of the body has routine projections
ABCS
A-alignment
B-Bone Density
C-Cartilage Assessment
S-Swelling
what is the significance of alignment in an x-ray
Size of the Bone Number of Bones Shape of Bones Contour of BOnes Bone and Joint position Most common cause of mal-alignment is trauma to the joint (muscle may appear more radiodense than normal)
what is the significance of bone density in an x-ray?
Bone quality gives you the degree of mineralization
Normal bone should be close to radio-opaque
Fine lines are trabeculae - normal healthy bone have this
issues with bone density
- erosive hand sclerosis - issue with bone density, increased whiteness in the carpals because there is bone to bone contact and less radiodense in the fingers
- osteopenia - early diagnosis for osteoarthritis
Cartilage assessment significance
Indirect assessment, looking for space between joint to be parallel and radiolucent, are spaces between bone equal and big?
Swelling significance
- swelling appears when there are issues in the soft tissue
- degree of contrast will not be the same as normal
- fat pad sign is radiolucency anteriorly is fine, but posteriorly means that there is a fracture in the joint
