MRI Without Contrast is Recommended for Cervical Spine Nerve Impingement
For nerve impingement in the cervical spine, MRI without contrast is the recommended imaging modality in most clinical scenarios. 1
Rationale for MRI Without Contrast
MRI without contrast is the preferred imaging modality for cervical spine nerve impingement for several key reasons:
- Provides excellent visualization of neural structures including nerve roots and spinal cord
- Effectively demonstrates soft tissue pathology that may cause nerve compression
- Allows assessment of cord signal changes secondary to spinal canal narrowing
- Affords the ability to evaluate exiting nerve roots in the setting of radiculopathy 1
- Does not expose patients to ionizing radiation
Clinical Algorithm for Imaging Selection
Initial Imaging Approach:
- Start with plain radiographs of the cervical spine as the first-line imaging test
- Proceed to MRI without contrast if:
- Radiographs show degenerative changes
- Patient has neurologic symptoms or radiculopathy
- Clinical suspicion for nerve impingement persists despite normal radiographs
When to Consider MRI With Contrast:
MRI with contrast should be considered only in specific scenarios:
- Known malignancy with cervical pain or radiculopathy
- Suspicion of infection
- Assessment of leptomeningeal disease
- Post-operative evaluation to distinguish between scar tissue and recurrent disc herniation
Evidence-Based Recommendations by Clinical Scenario
Chronic cervical pain with neurologic findings or degenerative changes on radiographs: MRI cervical spine without IV contrast is usually appropriate 1
Radiculopathy with suspected nerve root impingement: MRI without contrast has high diagnostic accuracy (94.5%) for demonstrating exit foraminal disease 2
Suspected spinal cord or nerve root injury: MRI cervical spine without IV contrast is the appropriate next imaging study 1
Patients with known malignancy: MRI cervical spine without and with IV contrast is appropriate, as contrast helps assess leptomeningeal and soft tissue involvement 1
Important Considerations and Pitfalls
Detection limitations: MRI has limited sensitivity (32-44.3%) for ossification of the posterior longitudinal ligament (OPLL), so CT may be preferred when OPLL is suspected 1
Avoid unnecessary MRI in trauma: For trauma patients with normal CT and no neurological deficit, MRI rarely demonstrates clinically significant findings that would alter management 3
Metal implants: If the patient has cervical spine hardware, titanium implants cause significantly less MRI artifact than stainless steel, preserving diagnostic quality 4
Adjunctive techniques: MR myelography can be a useful adjunct to conventional MRI for better detection of foraminal stenotic disease in cervical spondylotic radiculopathy 2
By following this evidence-based approach, clinicians can appropriately select MRI without contrast as the primary imaging modality for evaluating cervical spine nerve impingement in most clinical scenarios, reserving contrast-enhanced studies for specific indications.