Imaging quiz 1

• Anatomic

  Anatomic appearance and alignment (and adequacy)
• General architecture

  1. Assess size, appearance, and number of bones

  2. Assess for normal bone shape and contour

  3. Outline should be smooth and continuous

  4. Assess for normal position relative to nearby bones

  5. Look for fractures, dislocations, and subluxations
• Bone density

  • General bone density - assess for changes in a broad area
  • Cortical should be more dense on periphery
  • Cancellous should have consistent trabecular pattern
• Textural abnormalities

  Thin, lacy, coarsened, smudged, fluffy
• Local density changes

  • Assess one localized area
  • Higher density = more stress on bone or body trying to contain disease
• Cartilage spaces

  • Joint space width - assess for narrowing and loss of width/height
  • Subchondral bone - look for erosion of joint
  • Epiphyseal plates - assess in pediatric patients
• Soft tissues

  • Muscles - assess for wasting or swelling
  • Fat pads and fat lines - should be parallel to bone and to length of muscle, displacement = joint effusion, elevation or blurring = swelling of nearby tissue
  • Joint capsules - look for distension with hemorrhage/edema
  • Periosteum - assess for periosteal reactions
• Miscellaneous soft tissue findings

  Foreign bodies - can include gas bubbles and calcifications
• Fracture types

  • Transverse
  • Stress
  • Longitudinal
  • Oblique
  • Comminuted
  • Segmental
  • Spiral
  • Butterfly
• Imaging sequencing (MRI)

  T1 - highlights fat, T2 - highlights fluid, Anything that is bright on the T2 images, dark on T1 = fluid based tissue
• X-ray

  • Greater density of structure = greater ability to absorb energy (white)
  • Lower density - easier for x-ray to be transmitted and less energy is absorbed (dark)
  • Radiolucent - transparent, gas
  • Radiopaque - white, metal
  • gas (black) → fat (dark gray) → soft tissue (light gray) → bone (white) → metal (bright white)
• Pediatrics

  • Epiphysis - head of the bone (end of bone)
  • Physis - growth plate
  • Metaphysis - neck of bone
  • Diaphysis - Shaft of bone
• Anatomic Site and Extent of Fracture

  • Intra-articular - fracture on ends of bone, located within articular cartilage (articulating surface)
  • Extra-articular - anywhere outside the articular cartilage
• What causes transverse fractures?

  • tapping
  • tension
  • bending
• What causes a longitudinal fracture?

  • repetitive torsion loading (distance runner)
• What causes an oblique fracture?

  • compression
  • bending
  • torsion
• What causes a comminuted fracture?

  • crushing
  • penetrating
• Segmental is a type of what fracture?

  comminuted
• What causes a spiral fracture?

  • torsion
  • twisting
• What causes a butterfly fracture?

  • compression
  • bending