Musculoskeletal Radiography Flashcards
How many bones are in a dog’s body?
319 (tail length dependent)
What is the biggest bone in the dog?
Femur
What is the smallest bone in the dog?
Stapes
From top to bottom, what regions of the bone are these 4 arrows pointing to?
- Epiphysis
- Growth Plate
- Metaphysis
- Diphysis
What two questions should you ask yourself everytime you look at a radiograph?
- Is this image normal or abnormal?
- If it’s abnormal, is this a medical or surgical case?
What are the four radiographic densities of body tissues?
- Bone: 14
- Soft tissue/ fluid: 7
- Fat: 6
- Gas: 4
What is every line on a radiograph the result of?
Two of the four densities interfacing with eachother
What are the four radiographic signs?
Abnormal:
- Size
- Shape
- Density
- Location
How much calcium must leave the bone before it can be detected radiographically?
Between 50-70%
What bone would show the first signs of osteoporosis?
The mandible
When does the growth plate disappear?
At 9-12 months
How large does a lesion have to be before it can be detected radiographically?
5mm
What can cause bone disease?
- Trauma (acute or chronic)
- Infection ( bacterial, fungal)
- Neoplasia ( Primary bone tumours, metastatic)
- Metabolic ( Hyperparathyroidism, HOD, HO)
- Degenerative (DJD, osteoarthritis)
How does bone respond to disease?
- Periosteal Proliferation
- Lysis
- Periosteal proliferation + lysis
- Does nothing
How long does it take for bone lysis to begin?
6 days
- macrophages come in and begin cleaning up the bone
How long does it take for periosteal proliferation to begin?
10-14 days
What are the three kinds of bone lesions you can have?
- Aggressive
- Non-aggressive
- Degenerative
What are the radiographic signs of Bacterial Osteomyelitis?
- Cortical Lysis
- Periosteal Proliferation
- Increased intramedullary swelling
- Soft tissue swelling
e. g. Discospondylitis
What are the radiographic signs of Fungal Osteomyelitis?
- Cortical Lysis
- Periosteal Proliferation
- Increased intramedullary swelling
- Soft tissue swelling
What are the radiographic signs of a primary bone tumour?
- Cortical Lysis
- Periosteal Proliferation
- Increased intramedullary swelling
- Soft tissue swelling
In what animals do you tend to see primary bone tumours?
- Big breeds
- Older/ geriatric animals
- One bone
- Doesn’t cross joint space
- “away from the elbow, toward the knee”
In what animals do you tend to see Bacterial osteomyelitis?
- Any breed
- Any age
- Open wound
- Multiple bones
- Will cross joint
- Septicaemia in young dogs
In what animals do you tend to see Fungal osteomyelitis?
- young and old
- Endemic areas
- Multiple bones
- May cross joint
- Coccidiodiomycosis, Blastomycosis, Histoplasmosis
