week 1 -radiology Flashcards
describe plain film x-ray imaging
X-Rays are produced in the tube, then travel through air and the skin and tissue of the body to land on the receptor or film.
That receptor (film in older days and now often a computer basedreceptive area) is sensitive to x rays.*
The visualisation of structures is based on the natural contract between air, fat, water, bone and metal.
- Dense structures resist the passage of x rays and appear more white(radiopaque)* Less dense structures do not resist as much the passage of x raysand appear more black (radiolucent).
describe radiopaque
Dense structures resist the passage of x rays and appear more white(radiopaque)
describe radiolucent
Less dense structures do not resist as much the passage of x raysand appear more black (radiolucent).
what is a comon view of plain film x ray images
AP
anterior poterior
describe right posterior oblique
back is turned to imagery, slight rotation right
how many views are necessary for an X ray and why
preferablyperpendicular to each other
This allows you to evaluate structures in 3 dimensions
list the basics of a good quality image
Image Contrast (visibility of detail)
* Blur (visibility of detail)
* Noise / Mottle (improves spatial resolution).
* Artifacts (good technique)
* Distortion (good technique and ‘set up’)
* Compromises (technique – consider dose vs image)
list practical factors of a quality image
No viable artefacts on the image – good patient preparation.
* Good collimation (image must include all of the target area).
* Target or centre of target in the centre of the image.* Good contrast in the image.
* Marker on the image to denote side L or R.
name DR ABC’S
describe and Radiography
Alignment
Bone
Cartilage
Soft tissue
describe alignment
the alignment of skeletal muscles
overlay different images for comparison
allows us to comment on relationship between osseous structures (hard and mineralized connective tissues.
describe bone
osseous structures observed
Scrutiny of cortices, medullary trabecular patterns, general density, size, shape and configuration
Osteoporosis affects bone density
describe cartilage
Not visible on x-rays.
* shows as joint space.
* Smoothness of articular cortex, width and regularity of joint space, bone density of subchondral bone
smaller space can show arthritis
describe soft tissue
X-ray is not the best to assess soft tissue but it is often visible and should be assessed.
* The visibility of soft tissue depends on its density, tissue type and encapsulating fat.
* Skin line displacement can indicate swelling for example
what angle of the foot is dorsa planar
from above
what does a heel pad measurement show
thickness of pad of heel
