Musculoskeletal imaging

From greek.doctor
  • Imaging of musculoskeletal trauma
    • X-ray first
      • 2 directions are always needed!
        • Fractures are often visible in only one direction, so we need 2 x-rays from different perpendicular directions to evaluate
      • Evaluation of x-ray
        • Anatomical shape, form and alignment
        • Cortex and medullary structure
          • Medulla should have trabecular pattern
        • Surface of joint
        • Surrounding soft tissues
        • In children
          • Epiphyseal plates
      • Fracture
        • -> one part of the bone is displaced compared to the rest of the bone
        • If the distal part of the bone is displaced dorsally compared to the proximal part due to a fracture, it’s a dorsal fracture
      • Fat blood interface sign (FBI sign)
        • Horizontal fluid level outside the bone that forms as blood and bone marrow fat escapes during a fracture
      • Rule of 2s
        • Get 2 x-rays with perpendicular directions
        • Image 2 joints (proximal and distal to the injury)
        • Get images at 2 occasions
        • Get images of 2 limbs – for comparison
    • Then US/CT/MRi
    • CT
      • For complex fractures/tumors
      • Interverterbral discs
    • MRi
      • Best for soft tissue
      • Bone does not give signal on MRi, but fatty bone marrow is visible
      • For inflammatory processes, tumors, sports injuries (often involve ligaments and not bones)
  • Sesamoid bones
    • Can be present as a variant of normal anatomy or as a response to strain
    • Often embedded in tendons
  • Specific pathologies
    • Meniscus tear
      • MRI
    • Polytrauma
      • CT
    • Weber fracture (types of ankle fracture)
      • Weber A – Fibula fracture under the syndesmosis with tibia
      • Weber B – Fibula fracture at the level of the syndesmosis with tibia
      • Weber C – Fibula fracture above the syndesmosis with tibia
    • Don Juan fracture
      • Fracture of calcaneus
    • Shoulder
      • Fracture often accompanies dislocation
        • Dislocation -> head of the humerus ends up behind the coracoid process
      • Fracture of surgical head of the humerus is the most common
      • AP front-facing position