Musculoskeletal Radiography Flashcards
Radiographic technique
Anesthesia or sedation!
At least 2 orthogonal projections
Oblique projections (esp horse)
Stressed projections (instability)
Positioning
Center area of interest (joint - in middle, half bone above + below; bone - centralized with joints above/below
Apophysis
Ossification center of a bony outgrowth (such as tuberosity)
Cut-back zone
Irregular surface on bone as bone remodeling occurs in growth
Layers/structures of bone
Periosteum > cortical bone > endosteum > medullary cavity
Nutrient foramen - not to be mistaken for a fracture
Diffuse lesions
Metabolic disease (i.e. juvenile osteofibrosis)
Nutritional disease
Monostotic lesion
One bone
Causes: traumatic, infectious, neoplastic (primary osseous neoplasia - osteosarcoma)
Polyostotic lesion
Multiple bones affected
Causes: neoplasia (metastatic, round cell, multiple myeloma); infectious
Aseptic osteonecrosis
Occurs in epiphysis
Causes irregularity in bone
Scale of aggressiveness of osseous lesions by morphology
Solid, continuous > onion skin > hair on end palisading > sunburst > complex, amorphous
Patterning of osteolysis
Geographic
Moth-eaten
Permeative
Geographic osteolysis
Slow growing lesions/bone cysts
Localized to a region ~ one foci
Moth-eaten osteolysis
More aggressive
Multiple mid-large sized foci in a region
Permeative osteolysis
Thin cortices, whole bone hazy
Small pervasive osteolysis, focal extensive
Aggressive
Transitional zone
Region between defect and normal bone
Short, well defined > less aggressive
Long, poorly defined > more aggressive
Soft tissue swelling
Larger degree of soft tissue swelling tends toward more aggressive lesions
Aggressive v non-aggressive
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
Articular space
Some curved joints
Some flat (need to shoot straight through joint to get good image)
Structures of the joint
Articular space
Sub-chondral and peri-articular bone
*Articular cartilage not visible on radiograph
Positive contrast arthrogram
allows visualization of cartilage
Aggressive joint lesions
Subchondral bone destruction
Irregular, heterogenous, interrupted intra- or peri-articular bone production
Narrowing or collapse of articular space
Marked soft tissue swelling
Non-aggressive joint lesions
Osteoarthritis (DJD)
Sub-chondral bone sclerosis
Osteophytes
Joint effusion
