Musculoskeletal and joint imaging Flashcards
What is the principle of “One view is no view” in plain radiographs?
It emphasizes the need for at least two views (AP and lateral) to accurately diagnose MSK conditions.
Why is ultrasound useful in musculoskeletal imaging?
It provides excellent visualization of superficial soft tissues like tendons and muscles and allows for dynamic imaging.
What are the typical patient positions for a computed tomography (CT) scan?
Usually supine with axial imaging, though alternative positions may be used.
What is the average duration of an MRI exam?
Approximately 45 minutes, but it can extend up to 2 hours for complex cases.
Name three absolute contraindications for MRI.
Cardiac pacemakers, electronic stimulators, and metallic foreign bodies in the orbit.
What are the key steps in fracture healing?
Hematoma formation, organization of hematoma, fibrous callus formation, primary bony callus formation, and remodeling into secondary bony callus.
What is the Salter-Harris classification used for?
It classifies epiphyseal (growth plate) fractures in children.
Describe a torus (buckling) fracture.
It is an incomplete fracture where one side of the bone compresses without breaking completely.
What is the difference between a simple and compound fracture?
A simple (closed) fracture does not penetrate the skin, while a compound (open) fracture breaks through the skin.
Which imaging modality is best for detecting subtle bone fractures?
Computed tomography (CT).
What are three key radiographic features of metastatic bone tumors?
Osteolytic lesions, osteoblastic lesions, and alteration of bone architecture.
Which primary malignant bone tumor commonly affects the diaphysis?
Ewing’s sarcoma.
What is the characteristic sign of gout on radiographs?
Overhanging margin sign and periarticular erosions with preserved joint space.
What are the early and late radiographic signs of rheumatoid arthritis?
Early signs include soft tissue swelling and marginal erosions; late signs include joint ankylosis and deformities.
Which areas are most commonly affected by metastatic bone disease?
The axial skeleton, especially the spine and pelvis.
What periosteal responses indicate aggressive bone lesions?
Laminated (onion skin), spiculated (hair-on-end), and Codman’s triangle.
What MSK imaging modality is most useful for detecting soft tissue masses?
Magnetic resonance imaging (MRI).
What is the difference between osteolytic and osteoblastic lesions?
Osteolytic lesions involve bone destruction, while osteoblastic lesions involve bone formation.
Which bone tumor is characterized by a sunburst periosteal reaction?
Osteosarcoma.
What type of fracture results from a twisting force along the bone’s axis?
A spiral (rotational) fracture.
What are the radiological findings of tuberculous arthritis?
Uniform joint space narrowing, early subchondral cortex destruction, and “moth-eaten” bone appearance.
Which MSK condition is more likely to occur in immunocompromised patients?
Suppurative osteomyelitis.
