Tumor biology and incidence
- Localized area of bone with avascular necrosis
- Conditions associated with bone infarction:
- Trauma
- Alcohol
- Steroids
- Working in conditions requiring air compression and decompression (deep see diving, caisson workers )
- Gaucher’s disease
- Sickle cell disease
- Gout
- Bone infarction involving articulating ends of long bones (femur, humerus) or weight-bearing bones (talus) usually found early due to pain or joint involvement
- Bone infarction involving metaphysis or diaphysis generally asymptomatic
- Remain undetected until incidentally found or if patient experiences pathologic fracture or sarcomatous degeneration
Plain films
Size
Variable
Tumor effect on bone
- Irregularly serpiginous-shaped calcified periphery possible
- Patchy sclerosis ans lucency possible
- Linear densities generally appear within the lesion
Cortex
If cortex involved, spares outer one third while affecting inner two thirds
MRI
- May be diagnostic
- May see central marrow fat within the lesion
- May see classic "double ring" sign
- Manifests as an inner serpiginous margin of lower T2-weighted signal and adjacent outer ring of high T2-weighted signal intensity