MRI Selection for Chronic Lumbar Back Pain
For patients with chronic lumbar back pain, MRI lumbar spine without IV contrast is the preferred imaging modality when imaging is clinically indicated after 6 weeks of failed conservative management. 1
When Imaging is Appropriate for Chronic Low Back Pain
- Imaging is generally not appropriate for initial evaluation of subacute or chronic low back pain without red flags and no prior management 2
- Imaging becomes appropriate only after persistent or progressive symptoms following 6 weeks of optimal medical management, particularly for patients who are candidates for surgery or intervention 2, 1
- MRI lumbar spine without IV contrast is the recommended initial imaging study for patients who have failed conservative therapy and are potential candidates for surgery or intervention 2, 1
Why MRI Without Contrast is Preferred
- MRI without contrast provides excellent visualization of neural structures including nerve roots and spinal cord 1
- It offers high-resolution, multiaxial, multiplanar views with high contrast between soft tissues 3
- MRI is highly sensitive for detecting bone marrow abnormalities using T1-weighted and short tau inversion recovery sequences 2, 1
- MRI does not use ionizing radiation, unlike CT or radiography 1, 4
- MRI has superior soft tissue contrast for evaluating nerve root compression compared to CT 1, 4
When to Consider MRI With Contrast
- MRI lumbar spine without and with IV contrast is indicated when there is suspicion of:
When to Consider Alternative Imaging Modalities
- For suspected fracture (history of trauma, osteoporosis, chronic steroid use), consider radiography or CT lumbar spine without IV contrast 2, 1
- If MRI is contraindicated, CT myelography would be an appropriate alternative for assessing the patency of the spinal canal/thecal sac and neural foramina 5
- Standard CT without contrast can be considered if the primary concern is bony detail, but it is inferior to MRI for evaluation of soft tissues and neural structures 5, 4
Common Pitfalls to Avoid
- Ordering imaging too early (before 6 weeks of conservative management) in the absence of red flags can lead to unnecessary procedures and interventions 1
- Using CT as first-line imaging for radiculopathy is not recommended due to inferior soft tissue contrast 1, 4
- Overreliance on imaging findings alone, as structural abnormalities seen on MRI may be present in asymptomatic individuals and may not explain the cause of pain 6
- Failing to recognize that numerous studies have shown routine imaging provides no clinical benefit in uncomplicated low back pain and can lead to increased healthcare utilization 2