Musculoskeletal Radiography

Question 1

Radiographic technique

Answer 1

Anesthesia or sedation!
At least 2 orthogonal projections
Oblique projections (esp horse)
Stressed projections (instability)

Question 2

Positioning

Answer 2

Center area of interest (joint - in middle, half bone above + below; bone - centralized with joints above/below

Question 3

Apophysis

Answer 3

Ossification center of a bony outgrowth (such as tuberosity)

Question 4

Cut-back zone

Answer 4

Irregular surface on bone as bone remodeling occurs in growth

Question 5

Layers/structures of bone

Answer 5

Periosteum > cortical bone > endosteum > medullary cavity

Nutrient foramen - not to be mistaken for a fracture

Question 6

Diffuse lesions

Answer 6

Metabolic disease (i.e. juvenile osteofibrosis)

Nutritional disease

Question 7

Monostotic lesion

Answer 7

One bone

Causes: traumatic, infectious, neoplastic (primary osseous neoplasia - osteosarcoma)

Question 8

Polyostotic lesion

Answer 8

Multiple bones affected

Causes: neoplasia (metastatic, round cell, multiple myeloma); infectious

Question 9

Aseptic osteonecrosis

Answer 9

Occurs in epiphysis
Causes irregularity in bone

Question 10

Scale of aggressiveness of osseous lesions by morphology

Answer 10

Solid, continuous > onion skin > hair on end palisading > sunburst > complex, amorphous

Question 11

Patterning of osteolysis

Answer 11

Geographic
Moth-eaten
Permeative

Question 12

Geographic osteolysis

Answer 12

Slow growing lesions/bone cysts
Localized to a region ~ one foci

Question 13

Moth-eaten osteolysis

Answer 13

More aggressive
Multiple mid-large sized foci in a region

Question 14

Permeative osteolysis

Answer 14

Thin cortices, whole bone hazy

Small pervasive osteolysis, focal extensive

Aggressive

Question 15

Transitional zone

Answer 15

Region between defect and normal bone

Short, well defined > less aggressive

Long, poorly defined > more aggressive

Question 16

Soft tissue swelling

Answer 16

Larger degree of soft tissue swelling tends toward more aggressive lesions

Question 17

Aggressive v non-aggressive

Answer 17

Bone production: interrupted, irregular, fuzzy borders; continuous, smooth, sharp borders
Osteolysis pattern: Permeative, moth-eaten; geographic
Transitional zone: long, ill defined; short, well defined
Soft tissue: usually present; may be mild or absent
Speed of change; fast, slow

Question 18

Articular space

Answer 18

Some curved joints
Some flat (need to shoot straight through joint to get good image)

Question 19

Structures of the joint

Answer 19

Articular space
Sub-chondral and peri-articular bone

*Articular cartilage not visible on radiograph

Question 20

Positive contrast arthrogram

Answer 20

allows visualization of cartilage

Question 21

Aggressive joint lesions

Answer 21

Subchondral bone destruction

Irregular, heterogenous, interrupted intra- or peri-articular bone production

Narrowing or collapse of articular space

Marked soft tissue swelling

Question 22

Non-aggressive joint lesions

Answer 22

Osteoarthritis (DJD)
Sub-chondral bone sclerosis
Osteophytes
Joint effusion