Should I order a CT of the lumbar spine with or without contrast for a compression fracture?

CT of Lumbar Spine Without Contrast is Recommended for Compression Fracture

For evaluation of a lumbar compression fracture, CT of the lumbar spine without IV contrast should be ordered rather than with contrast, as contrast does not provide additional diagnostic information for fracture assessment. 1

Rationale for CT Without Contrast

Advantages of Non-Contrast CT

• CT without contrast provides detailed analysis of fractures extending to the posterior column of the vertebra
• Allows evaluation of the integrity of pedicles and posterior cortex
• Equal to MRI for predicting significant spinal stenosis and excluding cauda equina impingement
• Provides excellent visualization of bony details critical for fracture assessment 1

Why Contrast is Unnecessary

• CT with IV contrast does not provide additional information to CT without contrast for evaluation of spinal fractures and alignment 1
• CT without and with IV contrast of the lumbar spine is not typically performed as there is no diagnostic advantage to performing a single study with or without IV contrast 1
• Contrast administration adds unnecessary cost and potential risks without improving diagnostic yield 2

Imaging Algorithm for Compression Fractures

1. Initial Assessment: Begin with plain radiographs of the lumbar spine

   • Useful for initial evaluation in patients with history of osteoporosis or steroid use 1
   • Provides functional information about axial loading when upright

2. Secondary Imaging:

   • CT without contrast: For detailed fracture characterization, especially for posterior elements involvement 1
   • MRI without contrast: Alternative if assessment of acuity, bone marrow edema, or neural compromise is needed 1

3. Special Considerations:

   • If there is concern for underlying malignancy, infection, or inflammation, MRI without and with contrast may be more appropriate 1
   • For patients with significant artifact from metallic hardware, CT myelography can be considered 1

Important Clinical Considerations

Radiation Exposure

• Unnecessary CT scans contribute to excess radiation exposure (average of 979.4 mGy cm additional radiation exposure per extraneous CT) 2
• Avoid ordering both CT and MRI unless specifically indicated 2

Distinguishing Benign vs. Malignant Fractures

• If there is concern for a pathologic fracture, MRI is superior to CT for this distinction 3
• Signs suggestive of pathologic fracture on MRI include:
  • Convex posterior vertebral body border
  • Extension into the posterior elements
  • Abnormal marrow signal 1

Avoiding Common Pitfalls

• Don't automatically order contrast-enhanced studies for compression fractures
• Avoid duplicate imaging modalities that provide the same information
• Remember that CT cannot determine fracture chronicity as effectively as MRI 2
• For elderly patients with osteoporosis, consider the risk of additional compression fractures even with minimal trauma 1

By following this evidence-based approach, you can obtain the necessary diagnostic information for compression fracture assessment while minimizing unnecessary radiation exposure and contrast administration.