Approach to musculoskeletal imaging Flashcards
0
Q
Types of bone lesions
A
- fracture
- sclerotic (pathologic thickening of the bone)
- lytic (a “punched-out” area of severe bone loss)
- periosteal new bone
- exostosis (a benign outgrowth of cartilaginous tissue on a bone)
1
Q
Factors influencing xray images
A
- tissue composition (radiodensity
- tissue thickness
- position of the object wrt film and X-ray source
- object shape
- superimposition of tissues
2
Q
radiolucent lesion
A
Destructive
lytic
erosive
3
Q
radio-opaque lesion
A
sclerotic
radiodense
dense
osteosclerotic
4
Q
different patterns of periosteal new bone
A
- solid/linear
- lamellated (onion skin)
- sunburst (hair on end)
- codman’s triangle (at an angle)
5
Q
Structure of long bone
A
- shaft
- metaphysis
- diaphysis
- epiphysis
- articular surface
- elevations
- facets
- depressions
- holes
6
Q
things to look out for in a bone/joint film
A
- identity
- 2 views or more (eg. A-P and lateral)
- alignment (dislocation or subluxation; developmental deformity? associated with another disease process?)
- joint surfaces and joint
- bone outline
- trabecular bone and lines
- soft tissues
- growth plates
- invisible structures
7
Q
What are the 2 views normally used in an xray?
A
- Anteroposterior (A-P)
- lateral
sometimes:
-swimmer’s view
8
Q
systematic approach to C-spine xray
A
- Coverage - adequate?
- Alignment - anterior/ posterior/ spinolaminar
- Bones - cortical outline/ vertebral body height
- spacing - discs/ spinous processes
- soft tissues - prevertebral
- edge of image
9
Q
Things to look out for in alignment
A
- Joint dislocation or subluxation
- fracture
- developmental deformity
- deformity associated with another disease process?
10
Q
Important things to look out for in joint xray
A
- smooth outline subchondral bone
- symmetrical joint space
- congruity between articular surfaces
- fluid, calcification, gas within joint
11
Q
Things to look out for in the soft tissues in an X-ray film
A
- masses
- calcification (fluffy amorphous density)
- ossification (bone formation in organized pattern with a cortex and medulla)
- gas
12
Q
Appearance of fractures on plain film
A
- Dark streaks or lines across the bone - line usually transverses both trabecular and cortical bone (break in the cortex)
- White line - double density due to bone overlap
- Comminuted - more then 1 fracture plane
- Deformity - abnormal alignment
- Bone ends may be separated by soft tissue swelling and haemorrhage
13
Q
How to identify fractures?
A
look for
- break in cortex
- radiolucent lines across the bone
- white line or area due to overlap of bone
- fragments of bone
- denser white lines where trabecular bone is impacted
- mal-alignment of bones
14
Q
Pros and cons of plain films
A
- good overview of bones and joints
- Good for alignment
- Flexibility in positioning
- less contrast/ spatial resolution than CT
- radiation, but less then CT
- Cheap and quick
- Readily available
15
Q
Pros and cons of CT
A
- More detailed (esp complex joints/ fractures)
- multiplanar imaging
- More expensive than plain film
- more radiation
16
Q
Pros and cons of MRI
A
- Good spatial and contrast resolution
- good for soft tissue and bone marrow
- good for inside joints (hidden structures)
- cross-sectional imaging
- imaging in multiple planes
- no radiation
- limited functional information
- contraindications (pacemaker, cochlear implant, some aneurysm clips)
- more expensive
- longer scan times
17
Q
Pros and cons of ultrasound
A
- operator dependent
- high resolution for superficial soft tissue structures (tendons, nerves, ligaments, muscle)
- small field of view
- does not see inside the joint or through bone
- readily available, cheap, dynamic, no radiation
18
Q
Pros and cons of nuclear medicine
A
- shows increased bone turnover and so activity pf lesions
- mainly used for metastatic disease, infection, stress fractures, arthritis
- sensitive but not specific
