Chap 1 & 2 Flashcards
(25 cards)
What is radiodensity?
Physical qualities of an object that determines amount of radiation it absorbs from an x-ray beam
What does radiodensity depend on?
•Dependent on:
•Atomic number (# of electrons with which an x-
ray photon can interact)
•Volume density
•Thickness
What is radiographic density?
Amt of blackening of an image
With a great radiodensity, we get ____________ resulting in a ____________ image
Less radiographic density, whiter image
With less radiodensity, we get ____________ resulting in a ____________ image
more radiographic density, darker
Radiopaque
Doesn’t easily penetrate xray - white
Because of great radiodensity. Ex: metal
Radiolucent
Easily penetrated by xray = darker image
Decreased radiodensity. Ex: air
4 major density = 4 shades of gray (radiographic density)
Air = black
Fat = gray-black
Water = gray
Bone = white
The thicker an object, the _________ radiodense it will be
More (lighter image)
Decubitus?
It describes both a body position on a horizontal surface and the use of a horizontal x-ray beam 
4 image quality factors
Density
Contrast
Detail = motion
Distortion = size/shape
Routine radiographs can prove 5 things. What are they?
Positive = right dx
Negative = wrong dx
Negative for one dx suspicion for another
Inconclusive = additional imaging needed
Wrong
Search pattern of Radiology = ABCS
Alignment
Bone density
Cartilage spaces
Soft tissues
Alignment
General skeletal architecture – Assess gross normal size, appearance & # of bones
What does it look at?
• Aberrant size of bones
• Supernumerary bone
• Congenital anomalies
• Absence of any bones
• Developmental deformities
Alignment
General contour of bone - Assess each bone for normal shape & contour
• Internal or external irregularities
• Cortical outline of each bone should be smooth & continuous
• Osteophytes, spurs
• Breaks in cortex continuity
Alignment
Alignment of bones relative to adjacent bones - Assess for normal positional relationships
• Fracture
• Dislocation
• Subluxation
Bone density = what are the main things we look for?
General bone density
Textural abnormalities
Local density changes
General bone density looks for?
Assess loss of bone density resulting in poor contrast btw soft tissues & bone as well as thinning or absent cortical margins.
• Sufficient contrast btw soft
tissue shade of gray & bone
shade of gray
• Sufficient contrast within each
bone- btw cortical shell &
cancellous center
Texture abnormalities = Assess appearance of trabeculae
thin, delicate, lacy, coarsened, smudged, fluffy.
• Normal trabecular architecture
Local density changes
Assess for excessive sclerosis, osteophytes
• Sclerosis at areas of ↑’d stress
Cartilage Spaces = they look at? 3 things
Joint space width
Subchondral bone
Epiphyseal plates
Joint space width
Assess ↓’d jt space for degen or traumatic conditions
• Well-preserved jt spaces imply
Subchondral bone
Assess appearance for sclerosis seen in DJD, erosions
• Smooth surface
Epiphyseal plates
Assess contralaterally for symmetry
• Depends on skeletal age
