Bone: Diagnostic Imaging Flashcards
Is an MRI or a CT more expensive?
MRI
When is the “right” time to x-ray to obtain the best imaging result?
From those cases where clinical signs are severe or persistent/recurrent despite treatment
What 6 things are altered for a good x-ray?
- Positioning
- Centring
- Collimation
- Exposure/processing (darkness, contrast, resolution)
- Labelling
- Artefacts
What views are needed for a radiograph?
- Take at least 2 views
- ± contra-lateral limb for comparison
What can bone abnormalities be classified according to within the skeleton to help understand what is going on? Give 2 examples (3)
Distribution
–Only one/many bone(s) involved
–Involving just one bone region (e.G. Metaphyses) or generalised (all regions)
–Symmetrical or assymetrical
What 3 things do we comment on with the presence of lesions on radiogrpahs?
- Number
- Size
- Shape
What 3 things do we comment on with the location of lesions on radiographs?
- Bone
- Region
- Surface
What 2 things do we comment on with the presence of lesions on radiographs?
- Radiopacity - bone production or lysis?
- Margination
Label
a. Medullary cavity
b. Endosteum of cortex
c. Cortex
d. Periosteum surface
Label
A) Physis
B) Epiphysis
C) Metaphysis
D) Diaphysis
E) Metaphysis
F) Epiphysis
G) Physis
What is the term for bone loss?
Osteopenia
Osteopenia is always bad, but what are the 2 forms?
- Reversible e.g. Disuse – reduce loading, but if you load again it will loose again
- Irreversible e.g. Neoplasia
What is sclerosis?
Increased bone density
What is Wolff’s law?
Response to increased or abnormal loading
What can sclerosis be in response to? (2)
–Response of bone to wall-off ‘pathology’ e.g. infection, cyst
–Response to increased or abnormal loading: Wolff’s Law
Discuss this radiograph?
Hip dysplasia, cranial acetabulum edge increased opacity
Discuss this radiograph
Bone infection – surrounding has increased opacity
Name two things giving an appearance of new bone (3)
- Superimposition of structures (bone or soft tissue)
- Adjacent bone loss
- Foreign material e.g. on coat
Name a cause of an appearance of bone loss on radiographs (2)
- Gas, or defect in soft tissues
- Mach lines – where 2 bones overlap (mimics hairline fractures)
Define an aggressive lesion
Rapid bony change = minimal time for bone to remodel. Appearance is disorganised
Define a non-aggressive lesion
Slow-growing, benign more chronic process – remodelling possible. More structured reaction.
What 6 things do we look at to assess appearance of lesions?
- Bone destruction (lysis)
- Periosteal reaction
- Lytic edge character
- Cortical disruption
- Transition from normal to abnormal bone
- Rate of change (10-14 days)
Label these bone lysis patterns
A) Geographic lysis - least aggressive
B) Geographic lysis - more aggressive
C) Moth eaten lysis
D) Permeative lysis
Label these periosteal reaction patterns
A) Solid
B) Lamellar (parallel)
C) Lamellated
D) Thick brush like
E) Thin bursh like
F) Sunburst
G) Amorphous bone production
If there is a varying degree of aggressivenes in a lesion, how would you analyse the aggressiveness?
Use the most aggressive aspect
How aggressive is degenerative joint disease?
Non-aggressive
How aggressive is neoplasia?
Aggressive if malignant, non-aggressive if benign
How aggressive is an infection?