Anat - Imaging of the Musculoskeletal System Flashcards
What factors influence the final xray image?
Tissue composition (radiodensity) • Tissue thickness • Position of the object wrt film and X-ray source • Object shape • Superimposition of tissues
Are the densities from most to least dense?
Lead Bone Muscle Blood Fat Air
What are some factors which influence the appearance of the object?
Tissue thickness
Object shape
Which directions do we look at bones from?
Usually across and so the anterior and posterior components add up
Tubular bone = denser margin
Are densities additive?
Yes
What is the epiphysis?
The region of the epiphysial growth plate - sometimes still referred to even in adults when it has fused
What are trabecla?
Bony struts with marrow inbetween
Where is cancellous bone found?
At the prximal and distal ends
How many secondary epiphysis in the shoulder?
3
What can be seen in place of an epiphysis?
A white line (the remnant of the growth plate)
What is a nutrient foramen?
All bones possess larger or smaller foramina for the entrance of the nourishing blood-vessels; these are known as the nutrient foramina, and are particularly large in the shafts of the larger long bone
What is a suture in the skull?
It is a fibrous joint which can remain well into adultood
What covers the bone after the synovial joint?
Periosteum
What are we looking at when we see a film?
- Identity
- 2 views or more (projections)
- Alignment
- Joint surfaces and joint
- Trabecularbone and lines
- Bone outline
- Soft tissues
- Growth plates
- Invisible structures
How should the glenoid and the humeral head be positioned?
They should be congruent, they need to contact
What is the angle between the humerus and the
140
how should the shoulder be positioned for best function?
?
What films are used for most joint?
AP and lateral
What projections are used for the shoulder?
– AP – Lateral – Internal and external rotation – Axillarylateral – AP with cranio-caudal downtilt
Common fractures after dislocation of the shoulder?
v
Most common type of shoulder dislocation?
Antero-inferiro
Growth plates in the shoulder?
Lesser
Greater (tuberosity)
Humeral head
How many growth plates on the acromium?
3
How is the elbow usually visualised on x-ray?
– AP
– lateral
– AP oblique
