II. Indications (with normal L-Spine XRay)
- Osteomyelitis
- Bony neoplasm or metastases
- Occult Vertebral Fracture
III. Mechanism
- Radiographic tracer compounds taken up by new bone
- Technetium Tc 99m Phosphate
- Gallium 67 Citrate
- Incorporated into hydroxyapatite crystals
- Increased uptake indicates areas of high bone turnover
IV. Advantages
- Sensitive for bony neoplasm
- Test Sensitivity in spinal metastases: 85%
- Sensitive for infection
V. Disadvantages: Non-specific
- False Positives in 33% older patients (Osteoarthritis)
-
False Negatives
- Diffuse bony metastases
- Multiple Myeloma
VI. Protocols
- Technetium Tc 99m Phosphate
- Gallium 67 Citrate
- Most accurate imaging in infectious spondylitis (95%)
- Single-Photon Emission Computed Tomography (SPECT)
- Three dimensional bone scan imaging
- Lesions of Vertebral pedicles suggests malignancy