- Periosteal reaction
- Thin, linear periosteal reaction
- Thick periosteal reaction
- Laminated—"onion peel"
- Codman's triangle—periosteum forms bone only at the margins of the periosteal triangle
- Bone destruction
- Permeating bone lesion
- Punched-out bone
- Moth-eaten
- Geographic
- Aggressive osteolysis
- Well-defined osteolytic lesion with thick sclerotic border
- Localized cortical thickening
- Involucrum
- Reactive new bone surrounding sequestrum
- Ground-glass
- Diffusely dense bones
- CT—for evaluation of
- Chronic disease
- Soft tissue expansion
- Sequestra
- Sinus tracts
- MR—relative to X-ray
- Increased sensitivity
- Decreased specificity
- Nuclear Medicine
- Tc99m-MDP bone scan
- More sensitive than plain film
- Negative rules out osteomyelitis
- Phases (osteomyelitis positive through all 3 phases, cellulitis is negative on delayed)
- Flow
- Blood pool
- Delayed
- If underlying bone abnormal (i.e. diabetic foot, fractures, nonunion, pseudoarthroses, hardware) use multiple isotope scintigraphy (Tc99m-MDP combined with the agents listed below)
- Sulfur colloid
- Defines extent of red marrow
- Labeled WBC's (Indium-111 or Tc99m-HMPAO)
- Infection suggested by
- Activity in absence of sulfur colloid activity
- Greater activity than that of sulfur colloid
- If activity of labeled WBC's and sulfur colloid ~equal, probably just marrow not infection
- Infection suggested by
- Gallium
- Used in place of labeled WBCs
- Less effective
- Sulfur colloid
- Tc99m-MDP bone scan
- Risk factors
- Penetrating trauma
- Immunocompromised
- IV drug abuse
- Diabetes mellitus
- Sickle cell disease
- Sequestrum and/or abscess
- Antibiotics and surgical drainage
- In patients <>
References:
- Weissleder et al, Primer of Diagnostic Imaging, 4th edition, 2007.
- Bookstein, Medical Student's Pocket Reference, 4th edition, 2002.
- Brant & Helms, Fundamentals of Diagnostic Radiology, 3rd edition, 2006.
- STATdx, url: my.statdx.com (by Amirsys, Inc.).
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