What is the next best step if an MRI (Magnetic Resonance Imaging) of the cervical spine is questionable for myelopathy?

Next Best Step for Questionable MRI Findings in Suspected Myelopathy

When MRI of the cervical spine shows equivocal findings for myelopathy, CT myelography is the next best step to clarify the diagnosis and guide treatment decisions. 1

Primary Recommendation

CT myelography should be performed when MRI findings are equivocal or questionable for myelopathy. 1 The American College of Radiology (ACR) Appropriateness Criteria explicitly state that CT myelography may prove useful in diagnosing foraminal stenosis, bony lesions, and nerve root compression in the setting of equivocal MRI findings. 1

Clinical Context and Rationale

Why CT Myelography After Equivocal MRI

• CT myelography provides superior visualization of severe canal stenosis and can answer specific questions before surgical intervention when MRI is inconclusive. 1
• This modality is particularly valuable for evaluating bony encroachment, disc-osteophyte complexes, and the degree of neural structure compression with better osseous resolution than MRI alone. 1
• CT myelography can diagnose severe canal stenosis in spondylotic myelopathy when MRI findings are uncertain. 1

Important Clinical Considerations

Prompt action is critical because delayed diagnosis of cervical spondylotic myelopathy leads to long-term disability. 2 The hallmark symptoms to assess include:

• Decreased hand dexterity and gait instability 2
• Progressive sensory and motor dysfunction 2
• Upper motor neuron signs on examination 2

Alternative Scenarios

When to Consider Repeat MRI with Contrast

If demyelinating disease, inflammatory conditions, or spinal cord ischemia are in the differential diagnosis rather than compressive myelopathy, MRI with IV contrast should be obtained instead of CT myelography. 1

• Contrast-enhanced MRI is recommended for initial diagnostic evaluation of demyelinating diseases like multiple sclerosis or neuromyelitis optica. 1
• Diffusion-weighted imaging should be included when spinal cord ischemia is suspected, as it shows signal alteration earlier than T2-weighted images. 1

When MRI Cannot Be Performed

CT myelography serves as the primary alternative imaging modality in patients with contraindications to MRI (e.g., pacemakers, severe claustrophobia, metallic implants). 1

Common Pitfalls to Avoid

• Do not assume degenerative changes on MRI correlate with clinical symptoms. Spondylotic changes are common in asymptomatic patients over 30 years of age and correlate poorly with neck pain alone. 1
• Do not delay surgical referral while pursuing additional imaging if clinical myelopathy is evident. Patients with moderate-to-severe clinical myelopathy require operative treatment regardless of imaging nuances. 2
• Do not order plain radiographs or CT without myelography as the next step. These modalities lack the soft-tissue resolution needed to evaluate the spinal cord and neural compression adequately. 1

Surgical Referral Timing

Refer to a spine surgeon promptly for any patient with suspected myelopathy, even while arranging CT myelography. 2 The natural history of cervical spondylotic myelopathy is often insidious with variable progression, and delayed diagnosis results in debilitating spasticity and weakness. 2, 3

• Patients with mild myelopathy may be treated surgically or nonoperatively 2
• Patients with moderate-to-severe disease require operative treatment 2
• Inaccurate radiographic diagnosis is an identifiable cause of poor surgical outcomes 4