Bones

Question 1

Causes of diffuse loss of bone opacity

Answer 1

Metabolic - Disuse- Nutritional

Question 2

Geographic pattern of osteolysis.

Answer 2

big >10mm areas of bone lysis, well demarcated with short transition zone. Usually non-aggressive, benign masses, may cause periosteal thinning by mass effect and displacement. E.g. bone cysts

Question 3

Penumbra effect?

Answer 3

It is scattering near the edges of the x-rayed object and may cause blurring on the xrays.
Penumbra is a part of the shadow- ‘partial shadow’ that appears between complete shadow and non-obscured area.

Question 4

Osteoporosis vs osteomalacia

Answer 4

both can cause diffuse loss of bone density (and radiodensity)
osteoporosis- is a loss of mineral component and bone matrix at the same ratio
osteomalacia (‘softening’) is a decrease in mineral component of the bone- the matrix is not mineralised enough (ricketts)

Question 5

Radiologic appearance of osteopenia

Answer 5

Osteopenia- loss of bone radiodensity.

• ‘Ghostly’ bones in comparison with soft dissue.
• coarse trabecular pattern as a smaller trabeculae dissappears first,
• sclerosis of subchondral bone
• double cortical line when the intercorticalbone is reabsorb as well

Question 6

How long does it take for bone loss to be radiographically seen.

Answer 6

6-10 days

30-60% of the mineral content has to disappear to be radiographically seen

Question 7

Zone of transition

Answer 7

Is the area between bone mass and normal bone tissue
the better demarcated and narrower the zone is the better prognosis.
short and ill-defined zone of transition can indicate malignancy

Question 8

Wolff’s law

Answer 8

bone adapts itself to pressure/loads that influence it by remodelling and changing internal architecture

Question 9

Name patterns of focal bone loss

Answer 9

• geographic
• moth-eaten
• permeative
• mixed

Question 10

Subchondral bone

Answer 10

thin, dense layer of bone beneath articular cartilagethat appears more radiopaque than adjacent bone

Question 11

Folding (torus) fracture

Answer 11

Incomplete fracture, when the bone folds instead of crack due to its increased elasticity (young individuals/ loss of bone minerality)

Question 12

Apophysis

Answer 12

bone protruberance, location of ligament/tendons insertion, has its own centre of ossification

Question 13

Moth-eaten osteolysis

Answer 13

smaller, multiple areas of bone loss (3-10mm), may invade the cortex, less defined and shorted transition zone, may coalesce in bigger ‘geographic’ pattern. More malignant changes

Question 14

Types of periosteal reactions

Answer 14

1. Continuous: a) solid b)rough and solid c)lamellar d)lamellated e)brush-like
2. Interrupted: a) spicular b)sunburst c) amorphous

Question 15

Bone response to injury

Answer 15

bone lysis or bone production

Question 16

Physeal scar

Answer 16

radiologically seen line in the physis, mark after growth plate