| Modality | Indications | Advantages | Disadvantages | Comments* |
| Plain radiographs | - Baseline
- Excluding other conditions in differential diagnosis
- Monitoring disease progression
| - Inexpensive
- Easy to obtain
| - Abnormal findings usually not present at onset of symptoms, except in newborns
| - Sensitivity: 16 to 20 percent
- Specificity: 80 to 100 percent
- Normal radiograph at onset does not exclude osteomyelitis
|
| MRI¶ | - Identify location and extent of disease
- Evaluation of adjacent structures for extension of infection (soft tissues, growth plate, epiphysis, joint)
- Evaluation of difficult sites (eg, pelvis, vertebral bodies, intervertebral discs)
- Planning surgical intervention
| - No radiation risk
- Demonstrates early changes in the marrow cavity
- Improved demonstration of subperiosteal abscess
- Demonstration of concomitant septic arthritis, venous thrombosis, or pyomyositis
| - Costly
- Less useful in multifocal or poorly localized disease
- Requires more time than CT
- Young children may require sedation or anesthesia
- Not always available
| - Sensitivity: 80 to 100 percent
- Specificity: 70 to 100 percent
- Osteomyelitis unlikely if MRI is normal
- Repeat MRI seldom leads to management changes in patients with clinical improvement
|
| Scintigraphy | - Poorly localized symptoms (eg, young children who cannot verbalize)
- Multifocal disease
| - More useful than MRI in multifocal or poorly localized disease
- Demonstrates early changes
- Readily available
- May require less sedation than MRI
| - Radiation exposure
- Does not provide information about extent of purulent collections that may require drainage
| - Sensitivity: 53 to 100 percent
- Specificity: 50 to 100 percent
- Osteomyelitis unlikely if scintigraphy is normal
- May be falsely negative if blood supply to periosteum is interrupted (eg, subperiosteal abscess)
|
| CT | - Evaluation of cortical destruction, bone gas, and sequestrum
- Delineating extent of bone injury in subacute/chronic osteomyelitis
- Planning surgical interventions
- Evaluation of complications if MRI not available or contraindicated
| - Less time-consuming than MRI
- Does not require sedation
| - Expensive
- Increased radiation exposure
- Poor soft tissue contrast
| - Sensitivity: 67 percent
- Specificity: 50 percent
- Generally used only if other studies are not possible or inconclusive
|
| Ultrasonography | - Evaluate fluid collections in adjacent structures (eg, joint, periosteum)
- Monitor abscess resolution or progression
| - Inexpensive
- No radiation burden
- Noninvasive
- Portable
| - Does not penetrate bone cortex
| - Sensitivity: 55 percent
- Specificity: 47 percent
|
